In a prospective study, 169 patients with invasive squamous cell carcinoma of the vulva were treated by radical surgery. One hundred patients, without palpable inguinal lymph nodes, had a vulvectomy only, and the remaining 69 underwent vulvectomy in combination with groin dissection. Different prognostic factors were analyzed, and the results of radical surgery were evaluated. It was found that a small, exophytic, microscopically well differentiated tumor confined to one anatomic area will carry the best prognosis. Conversely, a patient with a large, endophytic, poorly differentiated tumor with inguinal lymph node metastasis will have the least favorable outcome. If there is metastatic spread to the deep inguinal node, Rosenmüller, the prognosis is quite bad. The crude five year survival rate was 56 per cent and the corrected survival ate was 65 per cent. Eleven patients died of early complications, seven of pulmonary embolism. It was concluded that radical surgery gives the best cure rate. It is suggested that operation for invasive squamous cell carcinoma of the vulva in all patients should consist of vulvectomy with primary skin grafting and bilateral superficial inguinal gland excision en bloc.