A series of 117 women with histologically defined, superficially invasive (1-5 mm) squamous cell carcinoma was evaluated to determine important histomorphologic variables, frequency of pelvic lymph node metastases, and outcome. Radical or modified radical hysterectomy with pelvic node dissection was usually performed for women with more than 1 mm invasion, whereas more conservative surgery was used when invasion was 1 mm or less. Depth of stromal invasion was the most important variable in predicting pelvic lymph node metastases. The overall incidence of pelvic node metastases was 5%, and the incidence of metastases in those patients with 3 mm or less and 3.1-5.0 mm of invasion was 2 and 13%, respectively. Although the risk of node metastases was significantly higher with deeper invasion, one patient with 2 mm of invasion had pelvic node involvement. Microscopic lymph-vascular invasion and degree of lateral spread of tumor were also associated with lymph node metastases, whereas tumor grade was not. There were no invasive recurrences in the series. We conclude that histomorphologic variables other than depth of stromal invasion should be considered when evaluating patients with superficially invasive squamous cell carcinoma of the cervix. We recommend that any trends toward less radical therapy for this disease be justified by equal cure rates and careful pathologic review.