Due to environmental concerns, plastic recycling and natural fiber composites have been given more attention lately. In Malaysia, mengkuang leaf fiber (MLF) has been identified as a potential candidate to be used as a reinforcing fiber. The combination of recycled polypropylene (r-PP) and MLF could result in an inexpensive and sustainable composite. However, the mechanical properties of this composite have not been fully studied. The aim of this work was to evaluate tensile, flexural and impact properties of r-PP/MLF composites with and without sodium hydroxide (NaOH) treatment and maleic anhydride-grafted polypropylene (MAPP). The composite consisted of 60 wt. of r-PP and 40 wt. of MLF. The composite was compounded by twin-screw extruder and test specimens were fabricated using an injection molding process. Generally, the tensile and flexural properties showed improvements, especially those with MAPP and alkaline treatment, compared to neat r-PP. Improvements in tensile strength and modulus of approximately 28 and 224 were achieved for r-PP/Treated MLF/MAPP composite respectively. However, an adverse effect was observed in the impact strength of the composite, which was expected due to the nature of short fiber employed in this work. © 2019 by the authors.