A sample of 908 Mozambican pregnant women with gestational age < or = 21 weeks (as measured by ultrasound) were followed fortnightly from their first antenatal clinic visit until the end of the perinatal period. All women attended two suburban/semirural antenatal clinics in Maputo. Only 9% were lost to follow-up. Pre-term delivery occurred in 15.4% of women and low birthweight (LBW) in 16.2%. Mean birthweight was 2.91 kg. Perinatal death occurred in 4.7%. This obstetric cohort provides valuable baseline data to be used as reference. With substantial efforts, the non-compliance with follow-up at birth could be kept at a low level.