Objective: To examine transforming growth factor beta 1 (TGF beta 1) gene polymorphisms in Turkish patients with nonsyndromic cleft lip with/without cleft palate (nsCL/P). Methods: A total of 205 Turkish subjects were included; 80 nsCL/P patients and 125 unrelated control individuals. Analysis of gene polymorphisms was carried out by polymerase chain reaction and DNA sequencing. Results: We found the substitution of a proline by a leucine at codon 10 (Pro10Leu) and the substitution of an arginine by a proline at codon 25 (Arg25Pro) in exon 1 of the TGF beta 1 gene in nsCL/P patients. Conclusion: This is the first report investigating prevalence of TGF beta 1 polymorphisms in Turkish patients with nsCL/P.