Aim of study: the purpose of this study was to dete Aim of study: rmine dental and skeletal effects of the Frog appliance utilized in distalization of maxillary molars in growing patients. Material and method: Ten female patients with Angle Class II molar relation were selected for this study. The mean age of the patients was 11 years and 9 months. All patients were treated with the Frog appliance for an average period of 7 months and 9 days. Cephalometric radiographs and plaster study models were made at two stages; before and after maxillary molar distalization by the Frog appliance. The cephalometric radiographs and the study models were analyzed and the collected data were subjected to statistical analysis. Statistical t-paired test was done to determine the significant difference between the pretreatment and posttreatment measurements. Results: The maxillary first molars were distalized Results: an average of 4.85 mm (p≤ .01) into a Class I molar relationship in an average period of 7 months and 9 days. During distalization, the first molars were tipped distally an average of 7.2° (p≤ .02), intruded 4.51 mm (p≤ .01) and rotated mesiobuccaly 7.98° (p≤ .01). Anchorageoss measured at the first premolars averaged 1.65 mm (p≤ .01), with mesiobuccal rotation of 3.98 (p≤ .01). The maxillary incisors were labially inclined 4° (p≤ .01). No significant skeletal changes were recorded except for A point. Conclusion: The first maxillary molars have been di Conclusion: stalized by the Frog appliance with significant distal tipping, intrusion and mesiobuccal rotation. Unfortunately it produced reciprocal anchorage loss in the first maxillary premolars and incisors teeth.