The effect of different wood flour sizes on strength and dimensional properties of wood-plastic compositeswere examined. Wood flour of different particle sizes viz; 1.00mm, 2.00mm and >2.00mm were compounded withrecycled low-density polyethylene (LDPE) at different wood/plastic ratio of 1: 1, 2: 3 and 3: 2. The results obtainedshowed that wood flour size > 2.00mm has the highest MOR and MOE values of 1.206N mm-2 and 2484.72Nmm-2while wood flour size of 1.00mm had the lowest MOR and MOE values of 0.505Nmm-2 and 2195.89Nmm-2 respectively.Also the results of the physical properties showed that wood flour size of 1.00mm had the lowest thickness swellingpercentage with mean values of 0.28% and 2.08% while water absorption percentage has mean values of 0.91%and 10.58% after 2 hours and 24 hours of water immersion respectively. It was observed that wood flour size of2.00mm and particle size >2.00mm had the highest thickness swelling and water absorption percentages. Thisshowed that strength properties of wood plastic composites increased with increased particle sizes whereas itsdimensional properties increased with decreased particle sizes. The results of analysis of variance carried out onmechanical and physical properties showed that particle sizes and wood/plastic ratio had a significant effect on themechanical and physical properties of wood plastic composites (p 0.05).