Beninseed oil was extracted using soxhlet extraction method and transesterified to biodiesel using sodium methylate. The oil and its biodiesel were characterized according to American Society for Test and Materials (ASTM) protocols; the fatty acid profile was determined by gas chromatography analysis method, the glycerine content was measured to estimate the completeness of the reaction while the mineral contents were measured by atomic absorption spectrophotometer. The results obtained shows that the properties are within the ASTM limits and similar to those of diesel fuel which led to the conclusion that is can be used as alternative fuel for diesel engines. Of particular interest is the cetane index of 50, which is higher than that of diesel which will allow it to be used neat in diesel engine except that the viscosity of 32 mm2/s is too high for direct use in diesel engine. The oil is 83.948% unsaturated and consists mainly of 35.075% oleic acid and 45.78% linoleic acids.