This study aimed to investigate and compare the qualitative and quantitative anatomical characteristics of Acacia mangium and Acacia hybrid in plantation forests in Vietnam. The qualitative and quantitative anatomical characteristics were evaluated according to the International Association of Wood Anatomists list of microscopic features for hardwood identification. In terms of qualitative features, A. mangium had a rough, hard, and fissured bark surface with a golden brown to dark brown color, whereas A. hybrid had a smooth and slightly scaly bark surface with greenish brown to greyish brown color, and yellowish white to pale white spots. Moreover, the heartwood–sapwood color and microscopic features of both species were identical. In terms of quantitative features, A. mangium had higher values in the tangential diameter of vessel lumina, vessel per square millimeter, ray number per millimeter, fiber length, and fiber wall thickness than A. hybrid, whereas A. hybrid had a higher ray height and lumen diameter than A. mangium. Thus, it is suggested that bark morphology and some quantitative anatomical characteristics can be used for identification and evaluation of wood quality between A. mangium and A. hybrid growing in Vietnam.