It all starts when a Smurf decides that Lazy Smurf is not really lazy, but suffering from a medical condition. "Doctor" Smurf is cooking up illnesses for Smurfs who don't even know they are "sick" until Doctor Smurf tells them so. Soon other Smurfs are trying to get in on the act offering newfangled cures for various supposed illnesses. While it's all fairly harmless at first, things get serious when Papa Smurf and the Smurfette get sick for real. Can Doctor Smurf really cure the sick?