We have presented a group of consecutive unselected cases, presenting the characteristics of slipping of the upper femoral epiphysis, in various stages, and in different types of individuals. It is evident that in early cases the treatment described effects early fusion of the epiphysis with excellent preservation of function. Cases of gradual slipping in which an acute injury supervenes give especially satisfactory results if promptly treated. Unless special indications arise, conservative treatment by manipulation into forced abduction and internal rotation, followed by the use of an ambulatory spica, is a satisfactory method of treatment, and should not be entirely discarded for more radical methods.