This study is interested in two-step biodiesel production meeting compatibility requirements in the biodiesel fuel standards by use of broiler chicken rendering fat extracted from a slaughterhouse as feedstock. Broiler rendering fat biodiesel (BRFB) was mixed with petroleum-based diesel fuel (DF) at the ratios of 10%, 20%, and 50%, respectively, so that the fuel blends named BRFB10, BRFB20, and BRFB50 were obtained successfully. The effects of BRFB blends on the performance, exhaust emissions, and combustion behaviors of single cylinder diesel engine with a direct injection were systematically investigated at different engine speeds in the case of full engine load. The values of CPmax and HRRmax of BRFB blends were observed to be higher as compared to those of DF. This is attributed to both the low cetane number of BRFB and rapid combustion of accumulated fuel in the combustion chamber throughout the long ID. The torque values of BRFB blends were observed to be higher as compared to those of DF. Moreover, the NOx emissions were obtained to enhance slightly whereas the quantities of smoke opacity, CO, HC, and CO2 emissions were noted to decrease by using the BRFB blends. The engine performance and emission test results showed that the ideal fuel mixture ratio is achieved with the BRFB20 blend.