OBJECTIVE Pregestational diabetes mellitus (PGDM) represents glucose intolerance that begins before pregnancy and is followed by the increased risk of neonatal and maternal complications. The aim of this study was to establish neonatal outcome in pregnancies with pregestational diabetes mellitus and the factors that had influence on it. METHODS This study included 27 pregnant women with insulin-dependant PGDM hospitalized during 2004 in the Institute for Obstretics and Gynecology, Clinical Center of Serbia, Belgrade. The control group consisted of 2 292 healthy pregnant women presented to the Institute within 2004. RESULTS Twenty-three (85%) infants of the women with PGDM had complications in comparison with 356 (15.5%) infants of the women in the control group, that was statistically significant difference (p < 0.001). Macrosomia was present in 8 (29.6%/0) and birth injuries in 6 (22.2%) infants of women with PGDM that was statistically significant difference (p < 0.001) in comparisom with the women in the control group who had 194 (8.5%) infants with macrosomia and 156 (6.8%) infants with birth injuries. The women with PGDM had 3 (11.1%) neonatal deaths and 3 (11.1%) infants were born with congenital malformations in comparison with the women in the control group without these complications. We established statisticaly significant correlation (p < 0.001) between glicoregulation before and during pregnancy in the women with PGDM and neonatal outcome. CONCLUSIONS The incidence of neonatal morbidity and mortality in the women with PGDM was significantely more frequent as compared with the normal population. Achieving optimal maternal glucose levels in women with PGDM both preconceptionally and during pregnancy is associated with significant reduction of neonatal complications.