Abstract: Sarcocephalus latifolius (Synonym, Nauclea latifolia) is a shrub commonly seen in the South East of Nigeria. It is widely applied as herbal remedy in the treatment of various illnesses. The effect of ethanol extract of the root of the plant on some serum electrolytes was studied. A total of thirty Wistar albino rats were used to determine serum concentrations of K+, Ca2+, Cl¯ and HCO3¯. The animals were divided into six groups of five rats each. Five groups labeled A, B, C, D and E, were administered orally with graded doses of root extract of Sarcocephalus latifolius at concentration of 300, 350, 400, 450 and 500 mg kg-1 body weight, respectively. The sixth group (Group F) was used as the control and its animals were simply sustained on normal diet and water. Administration of the extract lasted for twenty-one days after which the animals were sacrificed by cardiac puncture. K+, Ca2+, Cl¯ and HCO3¯ were determined from each sample and the mean concentration was calculated for each dose and the control. Potassium, calcium and chloride determination were done by colorimetric methods while determination of bicarbonate concentration was done by simple titration. Na+ was separately assayed, by flame photometer, from a set of 18 rats of six animals in each of three groups. For K+, non dose dependent increases were observed which was non-significant (p>0.05), for A, D and E but significant (p<0.05) for B and C. Ca2+ showed a dose dependent and significant (p<0.05) decreases, except for A (p>0.05). Decreases (p< 0.05) for C, D, E and (p>0.05) for A and B were observed for Cl¯. Serum bicarbonate appeared almost completely unaffected by the extract, showing no significant changes. Na+ levels were depressed for the two test groups, A and B compared with the control (group C), with test group B showing a significant decrease (p<0.05). From the analysis, it could be concluded that Sarcocephalus latifolius has the capacity to influence various electrolytes to physiologically important degrees. Significant reductions in sodium and calcium levels indicate the usefulness of the plant in treatment of hypertension and pain/fever, respectively. However, significant reductions in chloride may negatively affect the normal balance of fluid in the body. Therefore, more scientific research is needed to establish the best approach to optimizing the numerous medicinal potentials of the plant.