Sixty-one cases of neonatal septicaemia (NNS) identified by positive blood cultures during surveillance of infection at King Fahd Hospital of the University in Khobar, Saudi Arabia from September 1983-September 1988 were studied to evaluate the local pattern of pathogens and the risk factors for sepsis using a case control analysis. The incidence of NNS was 4.9 per 1000 live births (LB). Among inborn infants, birth weight specific sepsis rate ranged from 2 per 1000 liveborns among infants with birth weight > or = 2500 g to 150 per 1000 liveborns in those weighing < or = 1500 g. Factors significantly associated with septicaemia were foetal distress, low Apgar score at 5 min, and requirement for mechanical ventilation and umbilical catheterization. Similar findings were obtained with infants whose mothers had pre-eclampsia. Staphylococci were the major Gram-positive isolate occurring in both 'early' (< or = 48 h) and 'late' (448 h) onset septicaemia. The study highlights the importance of knowledge of local epidemiology of NNS to formulate antibiotic policy. It also suggests the need for reporting birth weight specific rates and for a larger case control study of risk factors for NNS.