The aim of the study was to determine the incidence rate of individual types of clefts, association with other congenital defects and family incidence of the disease as well as evaluation of the condition of neonates born with cleft.Material and methods. Retrospective studies were performed in 2500 patients with cleft lip and palate treated at the Hospital and Clinic of Plastic Surgery in the years 1979-2003. There were examined 1650 patients with cleft lip with/without palate (CL±P) and 850 patients with isolated cleft palate (CP). In the group of 1650 cleft lip and palate subjects there were 775 patients with complete unilateral cleft lip and palate (UCLP), 250 patients with complete bilateral cleft lip and palate (BCLP) and 625 patients with cleft lip (CL).Results. 1. The incidence rate of CLP: CL: CP was approximately as 5: 3: 4. Unilateral clefts were 3 times as common as bilateral clefts and they occurred twice more often on the left side. 2. CLP occurred predominantly in males- M:F ratio = 1.8 : 1; in CL- M:F = 1.3 : 1 while reverse proportions were observed in CP patients, F:M = 1.38 : 1.3. A relationship was found between the condition of the neonate as evaluated by Apgar score and the body mass and coexistence of a specific cleft. The lowest Apgar score and the lowest birth weight was observed in neonates with BCLP, while neonates with CL had the highest values. 4. There is a proportional relationship between the severity of cleft and the incidence of the defect in first degree relatives. 5. 11% of cleft patients also develop other congenital deformities, including defect syndromes, which account for 24% of all associated defects.