This study aimed to investigate the effect of martensite particle size on dry sliding wear properties of dual phase PM steels. For this purpose, atomised iron powder with 0.3 wt.% graphite powder was cold pressed and sintered at 1200 degrees C. Some of the sintered specimens were annealed at intercritical heat treatment temperature of 750 degrees C and water-quenched to obtain coarse martensite region. The others were first austenitized at 890 degrees C, water-quenched and subsequently re-annealed at intercritical annealing temperature of 750 degrees C before rapidly water re-quenching to produce fine martensite size. Wear tests were performed in a pin-on-disc test device under 25 N load at 125 m min(-1) sliding speed. The wear rate decreased with decreasing martensite particle size due to the reducing inter-martensite particle spacing, increasing hardness of ferrite phases and decreasing cracking of fine martensite particles.