To develop a prenatal ultrasonographic (US) classification of cleft lip with or without cleft palate (CL-P) and correlate the classification with fetal outcome. During a 5-year period (1988 to 1993), 65 fetuses with CL-P were identified with prenatal US at one of two referral centers for high-risk obstetric cases. Sonograms from each case were prospectively and retrospectively evaluated. Clefts were classified into one of five categories: type 1, cleft lip alone (n = 5); type 2, unilateral cleft lip and palate (n = 15); type 3, bilateral cleft lip and palate (n = 20); type 4, midline cleft lip and palate (n = 21); and type 5, facial defects associated with amniotic bands or limb-body-wall complex (n = 4). The US classification correlated with severity of defect and fetal outcome. Type 4 and 5 clefts were universally associated with concurrent anomalies and a fetal outcome, type 1 clefts with a lower rate of anomalies (20%), and type 2 and 3 clefts with intermediate prognosis. Chromosome abnormalities also varied with the type of cleft as follows: type 1, 0%; type 2, 20%; type 3, 30%; type 4, 52%; and type 5, 0%. Prenatal classification of fetal CL-P correlates with fetal outcome. This classification should help counseling and management.