Of 193 children with Perthes' disease at the Texas Scottish Rite Hospital for Cripppled Children, 24 were found to have only minimal changes. The cases were grouped relative to the area of the femoral head involved, with 10 involving the anterior portion, seven the posteromedial, three the lateral, and four the central portion. Almost all hips lost some height as measured by the epiphysial index but all had good results by the Mose criteria irrespective of treatment. The anterior lesion is the same as that described by Catterall as Group 1. The three additional groups have a similar benign natural history but distinct radiographic features. The need for early recognition of these patterns is emphasised if unnecessary treatment is to be avoided. Possible correlations of these lesions with the segmental blood supply of the femoral head are proposed and an hypothesis relating the Catterall classifications to the blood supply is put forward.