A series of 117 patients with stage I vulva, squamous cell carcinoma was followed for 3-21 yr. Twenty recurrences (17.1%) were found, 12 in the vulva or vagina, 7 in the groin, and 1 in a patient who developed distant metastases. Tumor cell invasion in lymph or blood vessels was found in operative specimens from 19 patients (16.2%), 8 of whom (42.1%) developed local recurrences or metastases. Of 76 patients who underwent lymphadenectomy, 7 had ipsilateral and 1 had bilateral metastases to the inguinal lymph nodes. Five yr crude survival rate for the whole series was 79%, but only 52% for the group of patients with vessel invasion. Treatment should in most cases be hemivulvectomy with ipsilateral inguinal lymphadenectomy.