In this study, a bamboo stick board with rotary-cut bamboo veneers was successfully fabricated. Additionally, vacuum heat (VH) treatment, which is a popular thermal modification method, was used to modify bamboo sticks. Therefore, the effects of different VH treatment temperatures on the dimensional stability and flexural properties of bamboo stick boards with and without bamboo veneers were investigated. For all boards, as the temperature increased to 220 °C, the thickness change rate and equilibrium moisture content decreased, and the flexural properties increased. The results exhibited that VH treatment improved the dimensional stability and flexural properties of the boards. Furthermore, the board with veneers had lower flexural properties and higher thickness swelling after water absorption than the board without veneers (BSB). The results indicated that bamboo veneer caused low flexural properties and high thickness swelling of the board compared to the BSB. However, the bamboo veneer played an aesthetic role in the appearance of the bamboo stick board.