Background: Nonsyndromic cleft lip with/without cleft palate (nsCLP) is one of the most common birth defects of complex etiology, occurring in approximate to 1/700 live births worldwide. A series of epidemiological studies were conducted to investigate the association between a transforming growth factor alpha (TGF) polymorphism and nsCLP risk. The aim of this study was to investigate the association between the TGF/HinfI polymorphisms and nsCLP in Turkish patients. Methods: One hundred fifty-five Turkish subjects were enrolled: 70 nsCL +/- P patients and 85 unrelated control individuals. Genomic DNA was isolated from peripheral blood leukocytes, and molecular analysis of gene polymorphisms was carried out using polymerase chain reaction and restriction enzyme digestions. Results: We found significant difference between the TGF gene HinfI allele frequencies of the controls and: 1) the occurrence of nonsyndromic cleft lip (p=0.029,); 2) the occurrence of nonsyndromic cleft lip and palate (nsCL+P) cases (p=0.024; and 3) the occurrence of both nsCL +/- nsCLP cases (p=0.0365). The association between age of parents, gender, maternal exposures, socioeconomic status and clefts was assessed in each group separately. Conclusion: Our study indicates that the TGFHinfI gene polymorphism might be associated with nsCL +/- P susceptibility, thus contributing to the occurrence of nsCL +/- P in Turkish patients. The relatively small sample size of our study is one limitation of our study, and future research with larger specimen sets from different ethnicities will be required to validate our findings.