Separate clefts of the lip and of the palate (CL-CP) may belong to the same etiological class as the cleft lip with or without cleft palate CL(P), or a child may have two separate anomalies, CL and CP. This theory was tested in Finnish cleft patients. Among 2471 cleft cases, there were 66 CL-CP (2.7%). Adequate medical records were available for 62 children: 45 boys (73%) and 17 girls (27%). Familial occurrence was recorded in 6 cases (10%). Of the cleft cases among the near relatives, 5 were CL(P) and one CP. The prevalence of hypodontia was 37% among 38 subjects studied, as compared with 8.2% in the CL-, 29.8% in the CP- and 48.1% in the CLP controls. Conical elevations of the lower lip were observed in none, as compared with 0.8% of the CL(P)- and 39% of the CP controls. It was therefore assumed that the CL-CP belongs to the same etiological class as the CL(P).