Objective: To evaluate dental and skeletal effects of Twin Block-Headgear combination in treatment of Class II malocclusion cases. Material and Methods: Twenty five female growing patients with skeletal Class II due to both mandibular retrognathism and maxillary prognathism were selected. Fifteen patients were treated using Twin Block with high pull headgear (TB-HG group) for nine months, while the other ten patients had no treatments (control group). For each patient, lateral cephalometric x-ray film was taken at the start and the end of active functional treatment period and then traced and analyzed. The collected data were subjected to t test to assess the significant differences in the changes in measurements between the two groups. Results: The TB-HG group showed a significant maxillary growth restriction and enhancement of the mandibular growth. The upper and lower incisors were significantly retroclined and proclined respectively. The maxillary molars moved distally while the mandibular molars moved mesialy. The mandibular plane and palatal plane angles showed no significant changes. Conclusions: Twin Block-Headgear appliance could be used successfully in treatment of skeletal Class II malocclussion due to maxillary protrusion and mandibular retrusion without adverse changes in the mandibular plane angle.