Yes - if you want to have a party for him, by all means have one!!! We've always had parties for our boys (ages 2 and 5) - at age 3, he will understand what's going on and will be excited - even if there are only a few people there! You can include him in picking the invitations and theme for the party (curious george,trucks/cars....). I even made birthday cakes for my boys (pirate ship, boat, elmo...) - there's a ton of info online and it's really not that hard (and much cheaper than paying publix or wetakethecake...). As far as inviting his classmates, whatever you feel comfortable doing - I've never invited my boys' entire class, just their buddies - but I do have friends who have invited the whole class (it just gets expensive if you are having a party somewhere like mygym or jumpers....) If you need help w/ideas, let me know - I love planning parties :-)