My son is on the autism spectrum and still needs pull ups.  I've searched all over---the sizes for these types of "pull ups" for larger kids are very limited in stores---the small is too small and the large is too big.  I've found some through specialized websites, but the smallest size is still too big. My son is 5 and weighs 54lbs--the size small/medium are perfect for him.  They aren't as great as regular "pull ups" as far as not leaking---they have leaked after a long night of sleeping (my son also urinates a lot because he loves water).  So cut your little one off from drinks early evening :)