The aim of the research described in this paper was to determine the potential of RME in reducing particulate emissions from diesel engines. The tests were carried out at Emissions Testing Laboratory, Poznan University of Technology using the AMX-210/100 engine test bed. The AVL Micro Soot Sensor and Smoke Meter were used to measure PM emissions. The emission measurements were carried out over a 13-mode ESC cycle. The tests were conducted on a direct injection (common rail), turbocharged, Euro 4 compliant passenger car diesel engine. Four different diesel fuel/RME blends were tested. These blends contained respectively: 5, 20, 50 and 100% RME.