A retrospective cephalometric study of 50 consecutively completed Class II Division I malocclusion cases was carried out in order to analyse the resultant data for craniofacial features which might act as predictors for successful overjet reduction. All the patients had clinically measured overjets of between 10 mm and 15 mm at the start of treatment. The sample was subsequently divided into two groups depending on whether or not the overjet had been reduced to 4 mm or less at the end of treatment. No firm predictors were found, but the most favourable results were achieved with the Begg appliance.