The aim of the study was to investigate the possible relationship between maternal homocysteine levels and plasma lipid parameters and whether gestational diabetes can alter the serum maternal concentration of this substance. The study included 36 primigravidas divided into two groups: group A consisted of 21 healthy pregnant women with a mean gestational age of 38.2 weeks, and group B consisted of 15 diabetic women with a mean gestational age of 38.4 weeks. No difference in maternal homocysteine levels was noted between the two groups (6.006 +/- 1.64 vs. 7.004 +/- 1.36 micromol/L). Serum cholesterol levels and serum triglyceride levels in normal pregnant women were not statistically significantly different compared to those seen in diabetic pregnant women. Similarly, no difference was found between the two groups regarding LDL levels and atheromatic index. In women with diabetes there was a weak positive relation between plasma concentrations of homocysteine and LDL levels as well as atheromatic index, but this relation was not statisticially significant. We conclude that serum homocysteine levels are not elevated in women with gestational-onset diabetes. There was also no relation between serum concentrations of homocysteine and lipid parameters in this complication of pregnancy.