A procedure for administration of sodium benzylpenicillin (SB) to the brain was developed and tested on 22 rabbits. SB was administered drop-like intravenously in a dose of 200,000 units/kg body weight in combination with electrophoresis of the head area. It was shown spectrophotometrically that a single administration of SB increased its concentration in the liquor and brain tissues by 366.7 and 500 per cent respectively as compared to the control values. Practically no shifts in the EEG and ECG were observed which was indicative of safety of SB administration by that route. The procedure for intraorgan administration of SB in combination with electrophoresis may be recommended for clinical use.