A retrospective case-control study was designed to assess risk factors for neonatal infection. Nonprivate patients (8,215) who delivered in a period from January 1, 1983 to June 30, 1988 were studied. Ninety three cases of conjunctivitis (incidence 2.4/1,000), 104 cases of pneumonia (incidence 2.8/1,000), and 50 cases of sepsis (incidence 1.3/1,000) were identified. Group B streptococcus was cultured from septic neonates in 46%. Calculated Odds ratio's indicated prematurity/low birth-weight (OR 6.9) and antepartum fetal tachycardia (OR 6.3) as important risk factors for pneumonia/sepsis. Prematurity/low birth-weight (OR 3.0) and an abnormal presentation in the birth canal (OR 2.8) were identified as risk factors for conjunctivitis. After testing all the risk factors found by univariate analysis in a logistic regression model tachycardia (chi 2 35.21, p less than 0.001) remained an independent predictor for neonatal pneumonia/sepsis and abnormal vaginal presentation (chi 2 7.58, p 0.006) for conjunctivitis.