This study evaluated the properties of cement-bonded flakeboards made from wood of pioneer forest species, namely, Kelempayan (Neolamarckia cadamba) and Mahang (Macaranga gigantea). The wood species were first evaluated for their compatibilities with cement by looking at their effects on the hydration rate of the cement. The properties of the flakeboards were tested using ASTM D 1037-99. An analysis of variance was carried out to study the effects of accelerator types and concentrations and flake lengths on the boards. There was no significant interaction between the wood species, but there was a significant relationship between the differences of accelerator types and concentrations and flake length at p<0.05. Generally, boards treated and fabricated with higher concentration of accelerator and longer flakes had superior performance. The mechanical properties [internal bond (IB), modulus of rupture (MOR), screw withdrawal (SWD) and modulus of elasticity (MOE)] of the boards were significantly influenced by the length of the flake and accelerator concentration –– the longer the flake, the higher the accelerator concentration, the better the strength would be. For Kelempayan, the greatest values of MOR, IB, SWD and MOE which were influenced by flake length were 100mm Kelempayan at 1.5% MgCl2 (9.5 MPa), 100 mm Kelempayan at 1.5% MgCl2 (0.37 MPa), 100 mm Kelempayan at 2.5% MgCl2 (519.4 MPa) and 100mm Kelempayan at 1.5% MgCl2 (3329 MPa), respectively. As for the influence of accelerator concentration, the greatest mechanical values were observed from 75 mm Kelempayan at 2.5% CaCl2 (7.47 MPa), 75 mm Mahang at 2.5% MgCl2 (0.38 MPa), 75 mm Mahang at 2.5% CaCl2 (425.51 MPa) and 75 mm Kelempayan at 2.5% CaCl2 (3001 MPa), respectively. However, reverse results were recorded for the physical properties of Kelempayan flakeboards added with magnesium chloride (MgCl2).