The lack of a uniform, specific definition of microinvasive carcinoma of the cervix has made it difficult to extract from the literature a sufficient number of patients similarly defined from which to estimate the risk of nodal metastases or death from tumor. Factors potentially biasing the frequency of nodal metastases and death from tumor are examined, and series lacking such factors are used to provide estimates of the risk of metastases or death from tumor for various specific definitions, but the number of cases fitting each definition is too few at present to give reliable estimates.