I think it is good for the child to show interest in soccer, etc. You may encourage him to play chess, but don't try too hard to turn him into a chess player. Treat chess like any other board games (monopoly, snake and ladder). If he shows interest in the game, facilitate him. If he doesn't, don't get disappointed. There are other more important things in life than chess, such as your time spent with your grandson. Usually once a person (or a child) knows how to play chess, they will return to the game from time to time.
Grandfather dilemma

I will probably be breaking every chess rule here - but show him the Harry Potter with the live chess game - then get a comp game that is like war chess - this will get him interested and learning - there is always time later for serious study but getting him to learn the moves etc may be a way to go? Oh and if his mother finds out - blackmail her with the most embarassing moment of her teen life :P My dad does it to me and it works rotffffffffff

I agree that the first task is not to teach anything, but to get him interested. If it seems like work he wont care.
If not? Let him play football. It's probably better for his social upbringing anyway.

I'm with Scottrf on this one, just teach him the moves & let him go, you may get the next Jan Timman or Bobby Fischer if he developes his own style before he gets imprinted with all the book work & other ppls ideas. There's plenty of time for theory later

Last summer my grandson reached the age of 5 and I gave him my chessboard and chesspieces. I would love to teach him the game , but he's so young and rather wants to play football (soccer) or ride his magic bike. So far I didn't start teaching him anything yet.
When is a child ready to play ? What do I teach first ? Am I pushing him ? What if his mother finds out ?
I would love to get some advise on this matter .
Don't push him: if he wants to play super-pawns then let him but you'll be surprised how much he actually wants to know. Teach him some short games to memorise...

Hello pelly13,
from my point of view the best thing you can do if you want to spark his interest in chess is to play games with another person when he is arround. Usually the young kids immitate what they see around them. If he is interested he will ask you to show him how to play.
I have a friend who is a strength & conditioning coach and he often trains at home. His 4 years old boy likes to watch him in the gym and sometimes he starts to do some pushups, squats or he hangs on the pull-up bar. But this things are not imposed by his father, he does them because he enjoys them, not because he is forced to do so.

Ahh, very sweet little grandson Pelly.
Thing is its difficult to lose deliberately... and children need to win to want to play. If you lose every game and Im sure he will be fine.

Best way to do it is to take him to some place where other kids are playing, I mean a whole bunch of them, and they are all talking and discussing, and just having fun. If he is intellectually simulated and he has a 'chess' mind, he will want to get into it himself. You won't have to push.

Halftime summery :
So far I have been receiving only very positive reactions from you all. Thank you very much for that. All of them are very helpful and quite easy to implement. There are some simularities in the advices , but also very original alternatives. I can tell you all speak from the heart and/or own experience on the matter.

When I read this title I always think that this topic is about some paradox in the relativity theory. But apparently it is not...

Off:
Yes I've heard of the possible worlds theory. Our world just branches and every possible continuation exists in a separate world but no communication between those worlds is possible.
There is a world in which watcha does not disturb this topic with off comments. But unfortunately you stuck in this ugly one.

What if you wait until he starts to show interest in the game? My father didn't teach me how to play until I googled an image of a chess board and set it up, because I didn't show interest in it before.

Start him off with the simplest mates, let him walk a pair of rooks down opposite sides of the board to mate your king; that´s the stuff that interested me at five.

One thing that got me interested was my Aunt had a beautiful Marble set - she would clean the board and pieces whenever Iwas around - till I started to ask her about it and she started to teach me ( yes she didn't know much but she did know how all the pieces moved lol) .... so now that I am older and find outthere are openings, endgame, taticts ( specifically taught etc etc) it is like a whole new world.
Again tho at 5 - war or fantasy chess on the comp may be the go - I mean what kid doesn't like to watch a queen behead a knight?? * grinz* Yes stil a kid myself at heart ( altho hubby is like staunton staunton staunton!!!!!!)

@Flaming:
Still a kid at heart. I wish more adults had that in them. It helps one to keep a fresh and open mind. I can relate with you , I'm still a child myself and am not ashamed of it.
@All:
It doesn't matter what you tell (learn) a kid , the smart ones almost always ask the big question : WHY ? We didn't tell them to ask this question , it is inherently in them. The older we get , the less we ask this important question.
Most of the responses/advices on this thread revolve around this topic. The child , when stimulated (not forced !) will ask the question when he is ready for it. We , the adults , can only facilitate the environment , but it is the child that will decide to pick it up or reject it.
@Ajatsatru:
Don't get me wrong , I don't want to force my grandson in anyway and I will not be disapointed when he doesn't like chess. I don't want him to become a prodigy or GM . I learned the moves when I was 6 , but didn't play much until I was about 9 . I didn't feel my father was forcing me and I made up my own mind. In hindside though , I am glad he did teach me this beautiful game. And look at me , I will never be a strong chessplayer , but I still enjoy the game.
Last summer my grandson reached the age of 5 and I gave him my chessboard and chesspieces. I would love to teach him the game , but he's so young and rather wants to play football (soccer) or ride his magic bike. So far I didn't start teaching him anything yet.
When is a child ready to play ? What do I teach first ? Am I pushing him ? What if his mother finds out ?
I would love to get some advise on this matter .