The aim of this study was to compare the different treatment effects observed in Angle Class III patients treated either exclusively in the primary dentition or receiving treatment initiated during the early mixed dentition. 14 patients from five families were enrolled in this retrospective study. The treatment course, appliances, treatment length and treatment outcomes were compared. The skeletal changes were assessed by analyzing cephalometric radiographs taken prior to, during and after completion of orthodontic treatment. In those patients receiving treatment in the primary dentition only, the course of treatment was more continuous and only one appliance had to be used. Moreover, the treatment time was shorter compared to those patients starting treatment in the early mixed dentition (5.4 +/- 2.1 vs 21.1 +/- 9.7 months). Treatment exclusively in the primary dentition showed better dentoalveolar results.