Nine-five patients with squamous cell carcinoma of the cervix invading to a depth of 3 mm or less (microinvasive carcinoma) were retrospectively viewed in regard to the depth of stromal invasion, the width of horizontal spread, confluent invasion, vessel permeation and lymph node metastasis. The type of treatment and outcome were also evaluated. Confluent invasion was found in 6 patient (6%), and vessel permeation in 9 patients (9%). Lymph node dissections were performed on 85 patients, but no lymph node metastasis was found, irrespective of the presence of confluent invasion or vessel permeation. Fifty-five patients with no vessel permeation were treated by conization or total or modified racial hysterectomy, and none had a recurrence of the disease. Our results suggest that the presence of confluent invasion or vessel permeation does not influence the incidence of lymph node metastasis, but data in the literature indicate that confluent invasion and vessel permeation are risk factors for lymph node metastasis and invasive recurrence of the disease. We conclude that patients with invasion of depth 3m or less, with no confluent invasion and no vessel permeation, can be treated by conservative operation.