This paper investigates the fuel injection characteristics, engine performance, and emissions of a small single cylinder DI diesel engine using fuels of fatty acid methyl ester (FAME) such as methyl oleate (OME) and methyl laurate (LME). The delay in injection was examined by measuring the time difference between the start of pressure rise in the injection pipe and the start of injection. With OME there was a shorter injection delay than with ordinary gas oil. The results of the measurements of fuel injection rates also showed that FAME fuels prolong the injection and that the mean energy supply rates decrease due to the lower calorific value. Compared with gas oil, the FAME fuels showed similar brake thermal efficiencies at high loads, and the smoke densities were significantly lower under whole load conditions. The ignition delay with LME was similar to gas oil, while the OME showed better ignitability than LME.