In Nigerian ethnomedicine, Stemonocoleus micranthus Harms (Fabaceae) is used in the management of heart related diseases. This study investigated the effect of sub-chronic administration of methanol-dichloromethane stem bark extract of S. micranthus (SME) on lipid profile and histology of liver and kidney of rats. Adult albino rats of both sexes were randomly divided into four groups (n=5) and received daily administration of SME (100, 200, and 400 mg/kg) and 2 ml/kg distilled water (control) respectively for 28 days per oral. Biochemical tests were performed pretreatment and subsequently fortnightly as the treatment commenced. The results showed that the extract increased the serum high density lipoprotein cholesterol concentration while low density lipoprotein cholesterol, total cholesterol, triacylglycerol, and very low density lipoprotein cholesterol concentrations were reduced compared with the baseline values. However, the histopathological examination of the liver and kidney of the rats that received extract and solvent revealed normal portal area with bile ducts and hepatic artery as well as normal glomerulus and renal tubules without observable changes suggesting zero tendency of causing toxic effects. The preliminary phytochemical analysis showed that SME contained alkaloids, glycosides, flavonoids, reducing sugars, terpenoids, saponins, proteins and, fats oils. SME exhibited an oral LD 50 >5 g/kg in mice. These findings suggest that the stem bark extract of S. micranthus contains constituents that possess hypolipidemic activity in rats.