A nationwide cross-sectional survey covering the perinatal period was attempted throughout Greece for the 30 consecutive days of April 1983. It aimed to determine the perinatal mortality rate (PNMR) and the way it varied in the country in relation to underlying demographic, biological, socioeconomic and medical factors. For this purpose a coded questionnaire was completed by the obstetrician and/or the midwife responsible for (or, at least, present at) the delivery for every mother giving birth either to a livebirth or a stillborn infant weighing at least 500 g. All livebirths were followed until 7 days of age. The survey was administered centrally through a network of county-based co-ordinators. It resulted in the coverage of all state and private maternity hospitals, rural health centres and newborn units. In all 11,048 completed questionnaires were returned and 264 perinatal deaths reported, 42% of which had had a post-mortem examination. The crude PNMR was 23.8 per 1,000 births, with a stillbirth rate of 11.5 per 1,000 births and early neonatal mortality rate of 12.5 per 1,000 livebirths. This rate was substantially higher than would have been calculated from registration rates.