Properties of biodiesels are determined by the structural features of the fatty acids and the alcohol used for the transesterification. With accurate knowledge of the influence of the molecular structures on the biodiesel properties, the composition of oils and alcohol can both be selected to give biodiesel of optimal performance. A study was carried out to investigate the fuel properties of methyl esters, butyl esters and esters/diesel blends of Cucurbita pepo, Afzelia africana and Hura crepitans seed oils. The correlations between the fatty acids structures and the fuel properties were evaluated and they provided vital information that will enable formulation of optimal biodiesel blends from the oil crops. Both methyl esters and butyl esters of the feedstocks exhibited good fuel properties and compared very well with petroleum diesel and can be used as alternative fuel.