This study focuses on the development and characterization of polyurethane/bamboo fiber composites foams which have the specific properties to participate both in the thermal insulation and regulation of the humidity inside the building. The polyurethane foam reinforced by bamboo fibers (5–20 wt%) were produced to investigate the mechanical test, the morphological characterization and thermal properties. The result from mechanical test showed that the compressive strength was increased at 5 wt % of bamboo fiber. Likewise, the effects of the fibre diameter and nature of bamboo fibers on some properties (compressive test, thermal analyses, surface morphology) of bamboo fibre reinforced rigid polyurethane foam were studied. The bamboo Gai and Luong fibres result in composites with better mechanical strength than the other fiber composites.