Physical and mechanical properties of fire retardant-treated engkabang (Shorea macrophylla) and Acacia mangium particleboards were assessed. Tests selected for the assessments were water absorption, thickness swelling, modulus of rupture (MOR), modulus of elasticity (MOE) and internal bond (IB). The engkabang and Acacia mangium particles were mixed with 10% w/w of two different  fire retardants namely zinc borate (4Zn0.6B₂O₃.7H₂O)-simplified as ZBr and monoammonium phosphate (NH₄)H₂PO₄) during the mixing stage of the particleboard manufacturing processes. The properties of the particleboards were tested using British European 1993 standard. An analysis of variance was carried out to study the effects of fire retardant types on the boards of both species. The study showed that MAP-treated particleboards were superior to ZBr-treated particleboards for both mechanical and physical performances except for modulus of elasticity (MOE). Overall, the fire retardants reduced the physical and mechanical properties of the engkabang and Acacia mangium particleboards. However, all treated and untreated particleboards complied with the standard requirement values and these findings are expected to increase the promotion of both species to be used in producing fire-retardant particleboards.