Vegetable oil-based fuels are promising alternative fuels for diesel and light fuel engines because of their environmental and economic strategic advantages. In this study, we prepared the biodiesel from Congolese underutilized, nonedible Oleaginous Plant A. floribunda Oliv, and we determined its physicochemical properties according to the international standards for biodiesels and petro-diesels. A. floribunda oil was extracted and transesterified by alkali-catalyst using methanol with KOH as catalyst. The maximum yield of the obtained fatty acid methyl ester FAME (biodiesel) was 87.23%. The GC-MS Chromatography of the obtained fatty acid methyl ester FAME (biodiesel) showed the presence of Stearic acid, Oleic acid, Palmitic acid, Linoleic acid and Alpha-linolenic acid in the quantity of 61.68, 35.20, 1.15, 1.27 and 0.68%, respectively. Physicochemical properties (density, viscosity, flash, cloud and pour point; ash, water and sulfur contents; and corrosion on copper) values of Biodiesel (B100), and B20 (FAME blend in Gasoil), were within the range of values set by the international standards specifications of Petro-diesel and biodiesel (American Standard: ASTM D-6751 and European Standard- EN 14214). Thus, these two types of biodiesel (B100 and B20) could be used in a diesel engine in substitution of the Petro-diesel (Gasoil).