Good poems for a grandson's birthday include "Your smile is the solution," "Prouder than proud" and "You're a very special grandson." These poems are available on the Wishes Messages and All Great Quotes websites.
One short poem, titled, "Prouder than proud" reads, "Prouder than proud of the things that you do, you're a really cool grandson who's loved a lot too!"
Birthday poems for a grandson may highlight the grandson's accomplishments, the joy the grandson brings to his grandparents or the affection the grandparents have toward their grandson. Grandparents can recite a poem or write it on a birthday card to wish their grandson a happy birthday.