Increased exposure to gasoline and petroleum products is inevitable due to increased use for transport, power generation and even as substance of abuse. The effects of gasoline vapour on various body functions and electrolyte metabolism have not been fully understood. The present study was designed to investigate the effect of gasoline vapour on blood pressure, heart rate and cardiovascular reflexes and to determine plasma Na+ and K+ concentrations in rats. The Sprague Dawley rats used in this experiment were exposed to 27.8±1.7ml of wholly vaporized Premium Motor Spirit (PMS) blend unleaded gasoline (UG) for 6hr/day, 5 days/week, for 4 weeks in glass exposure chambers. The control rats were not exposed to gasoline vapour but were placed in the chambers. All rats were fed with standard rat chow and tap water ad libitum throughout the experimental period. The control and experimental rats were anaesthetized with sodium pentobarbitone (65mg/kg bodyweight) and dissected. The femoral artery was cannulated for blood pressure recording. The carotid arteries were isolated for test of cardiovascular reflexes by bilateral carotid occlusion (BCO) of 30 seconds duration. Heart rate was computed from the blood pressure pulse. Blood samples were thereafter collected by cardiac puncture for measurement of plasma Na+ and K+ concentrations. The results from the experiments revealed that chronic exposure to gasoline vapour induced a significant reduction in systolic pressure (from 131.70±4.6 to 95.40±4.3mmHg)(p< 0.05), diastolic pressure (from 100.00±6.1 to 62.00±5.1mmHg), mean arterial pressure (MAP) (from 110.57±5.4 to 73.13±4.7mmHg) and heart rate (from 419.20±14.8 to 363.30±6.4 beats/min). Baroreflex sensitivity tested by carotid occlusion was lower in the treated rats when compared with the control group. The plasma concentration of Na+ ions showed an insignificant increase (from 137.7±1.1 to 140.0±1.7 mmol/L; P>0.05) while K+ ions were significantly higher in treated rats compared with the control rats (from 4.7±0.4 to 6.5±0.3 mmol/L; P<0.05). This may be an indication of interference with membrane functions. These results obtained in this study indicate that exposure to gasoline vapour cause a reduction in cardiovascular functions and increase in plasma Na+ and K+ concentrations which may imply an alteration of metabolic processes.