Several techniques have been used to determine body composition during pregnancy.To determine the characteristics of body composition in women with gestational diabetes mellitus in comparison with women with normal glucose tolerance and pre-gestacional diabetes.Pregnant women with gestational diabetes mellitus, pre-gestacional diabetes, and normal glucose tolerance, between 24 to 32 weeks of single gestation, were enrolled in a cross-sectional study. Screening of DMG was carried out using 50 g of glucose load; diagnosis was confirmed by oral glucose tolerance test. Evaluation of body composition was carried out by bioelectrical impedance. The Kruskal Wallis test was used for statistical analysis.A total of 79 women were included; of these, diagnosis of gestational diabetes mellitus, pre-gestacional diabetes, and normal glucose tolerance was established in 14, 9, and 56 women, respectively. Pre-gestational body mass index was greater in women with diabetes (p < 0.01). Fat free mass and total body water were similar in the studied groups. Fat mass was greater in women with gestational diabetes mellitus (range 21.0-29.4 kg) and patients with pre-gestacional diabetes (range 26.4-32.7 kg) than in the women with normal glucose tolerance (range 150.8-25.9 kg), p < 0.01.The body composition of women, between 24 to 32 weeks of single gestation, is different in the women with gestational diabetes mellitus compared with women with normal glucose tolerance. Women with gestational diabetes mellitus show a significant increase in fat mass without significant changes in the fat free mass and total body water.