Abstract Introduction: Leptin is a polypeptide hormone (167 amino acids, molecular weight of about 16kDa), synthesized mainly in white adipose tissue. The hormone plays an important role in regulation of hunger and satiety processes, in metabolism of carbohydrates and fats, development of cardio-vascular diseases and obesity. The occurrence of the increased level of leptin in pregnant women with hypertension, especially in women with preeclampsia, has also been brought to our attention. In recent years it has been suggested that the presence of different variants of leptin and leptin receptor genes may modify the leptin level in serum, and, in this way, influence an increased risk of obstetric complications, such as preeclampsia or eclampsia. Materials and methods: We have analyzed a group of 103 hypertensive pregnant women – 61 women with gestational hypertension (GH) and 42 women with preeclampsia (PE). The control group consisted of 113 healthy pregnant women who have been investigated. Gestational hypertension and preeclampsia were recognized with the help of and assessed according to the ACOG criteria. The (-2548G/A) polymorphism was determined using polymerase chain reaction/restriction fragment length polymorphism (PCR/RFLP). Results: In our study, a higher frequency of mutated AA genotype in GH group and PE groups (21,31% and 21,43% respectively vs. 16,81% in the controls) and the overrepresentation of mutated A allele in both analyzed groups (47,54% and 45,24% respectively vs. 41,59% in the controls) have been observed, without statistically significant differences. Conclusions: The overrepresentation of AA genotypes and higher frequency of mutated A allele of (-2548G/A) polymorphism of leptin gene in GH and PE groups might indicate its possible contribution in gestational hypertension and preeclampsia.