The influence on cerebral hemodynamics of drugs given to infants less than 32 gestational weeks, at high risk for intracerebral hemorrhage, can be easily assessed by pulsed Doppler technique. We report on our studies in these infants who were treated with the following drugs: diazepam (0.5 mg/kg BW i.v.), pethidine (1 mg/kg BW i.v.), pancuronium bromide (0.1 mg/kg BW i.v.), phenobarbitone (loading dose = 20 mg/kg BW, maintenance dose 5 mg/kg BW i.v.), theophylline (loading dose = 6 mg/kg BW, maintenance dose = 1.5 mg/kg BW i.v.) and bovine surfactant SF-RI 1 (50 mg/kg BW intratracheally). All studied drugs proved to be safe at the administered dosage with regard to their influence on cerebral hemodynamics in very immature infants.