In this study, biodiesels were produced from five different vegetable oils, which were crude sunflower oil, crude soybean oil, refined soybean oil, refined poppy oil, and waste frying oil, by using transesterification method. Impacts of crude sunflower oil methyl ester (CSUME), crude soybean oil methyl ester (CSME), refined poppy oil methyl ester (RPME), refined soybean oil methyl ester (RSME), and waste frying oil methyl ester (WFME) on engine performance and emissions were tested on a single cylinder direct injection diesel engine at 1600 rpm engine speed. According to the results of the experiments, decreases in engine power and torque and increases in specific fuel consumption were obtained by the use of biodiesels. CO emissions were decreased when compared to those of diesel fuel. NOx emissions of CSUME and CSME fuels were decreased while NOx emissions of RPME, RSME, and WFME were increased with respect to the NOx emission of diesel fuel.