Summary
The Amazon Basin has bean called a zone of endemic hunger, however few representative scientific studies of human nutritional status have been carried out. Birth weight is influenced amongts other things by nutritional status. As data on the frequency of low birth weights in the Amazon was not available, 4168 birth records for the year 1976 were studied in two maternity clinics of Manaus. One clinic with 2552 births, attended principally the poor of the city, whilst the second attended 1614 births of a higher socio-economic level. The study represent some 25% of the estimated total number of births in the city for 1976. The frequency of low birth weight in the poor maternity clinic (11.7%) was higher than in the richer one (8.1%) (P<0,001). Attention is brought to the fact that most probably half of the poorest people in the city had their children at home. In comparison with other parts of the world these frequencies are intermediate between the north east of Brazil and developed countries, being only half of the frequencies found in Asia. The possible local factors responsible for these results are discussend and recommendations made that could improve the situation.