Environmental friendly pre-treatment of fibre has been lately adopted by many researchers worldwide but not fully understood. Although various chemical modifications of fibre through several chemical treatments have been explored, but less has been done on lower sodium hydroxide (NaOH) concentrations. This paper investigated the effect of thermalization at 115 C and lower NaOH of concentrations (1, 3 and 5) effect on mukwa wood flour as a way of minimizing chemical impact on possible manufacturing of eco-friendly wood polymer composites (WPC). Weight loss analysis was carried out to evaluate the effect of thermalization and alkalization modification. X-ray diffraction (XRD), thermogravimetric analysis (TGA) and scanning electron microscopy (SEM) were used to characterize the untreated and treated mukwa wood flour. The results showed significant surface modification thereby improving fibre characteristics as impurities (hemicellulose, lignin and other non-cellulosic substances) were removed.