A 12-month prospective study of infection was carried out in the special care baby unit (SCBU), Khoula Hospital, Muscat, Sultanate of Oman. During this period, 8720 babies were born in the hospital and 1265 were admitted to the SCBU. Altogether, 490 babies were of less than 36 weeks' gestation. A total of 190 babies (160 born in the hospital, 30 born before admission) satisfied the criteria for infection. The most common clinical presentation was pneumonia. There was one outbreak of iatrogenic infection. Infection was confirmed microbiologically in 76 of 190 symptomatic babies. Staphylococcus aureus was the most common pathogen and was isolated from 48 infected babies (25%). Beta-haemolytic streptococci were isolated from superficial sites only in eight babies. Klebsiella spp were the commonest enteric bacteria isolated, but they were rarely associated with infection. Of 46 babies who had bacteraemia, 9 also had meningitis. Nine of the 46 babies died, including 6 of the 9 who had meningitis. The mortality following Gram-negative infection was higher than that following Gram-positive infection. Fourteen per cent of infected babies born in hospital and 27% of those born before admission died. A high proportion of bacteria isolated were resistant to ampicillin and/or gentamicin. Results suggest that alternative antibiotics would be more appropriate for initial treatment. The study shows that in developing countries, unsophisticated research, using basic facilities, can be of value in identifying the problems of infection and in recognizing possible solutions to them.