Background: To study the etiology of late fetal death in Maputo. Patients: Stillbirths (n = 163) in Maputo were compared to 207 live births. Results: A probable cause of fetal death could be determined in 112 cases (69%). Hypertension was the most common factor associated with stillbirth and occurred in 14% of the fetal deaths, followed by abruption of the placenta (13%), syphilis (8%), clinical intrauterine infection (6%), malaria (4%), fetal malformation (4%), umbilicial cord complications (4%) and anaemia (4%). Mothers of stillborns and referent mothers differed in the following parameters: fetal weight, gestational age, numbers of previous stillbirths, haemoglobin, packed cell volume (p < 0.001), age, number of pregnancies (p < 0.01), parity, number of live children and skinfold thickness (p < 0.05). In the stillborn cases where no probable cause of fetal death was established, newborn weight was significantly lower and estimated gestational age significantly shorter (p < 0.001), number of previous pregnancies and number of previous stillbirths were significantly larger (p < 0.05) than in the referent group, but otherwise no significant differences were found. In two randomly selected subgroups, 28 mothers with stillbirth without probable diagnoses, and in 24 referent mothers, selected serum proteins and acute-phase reactants were determined. There were no statistically significant differences in the mean values of haptoglobin, pre-albumin, retinol-binding protein and α1-antitrypsin in the two subgroups. The stillbirth subgroup had significantly higher mean values of C-reactive protein and serum orosomucoid than the referent group (p < 0.01). Conclusion: Signs of maternal illness were present in one third of the mothers with stillbirth, and half of them required medical care. In one third there was no final diagnosis, but these mothers showed significantly higher mean values of acute phase reactants, suggesting low-grade infection.