The present study examined the wood properties of Pterocarpus erinaceus, a species found in West Africa's Guineo-Sudanian and Sudano-Sahelian zones. The primarily focus was on wood fiber properties, which serve as indicators of cambial growth and the transition between juvenile and mature wood. The aim was to analyze the factors contributing to the variability of the wood fiber properties. Specifically, it examined the effect of cambial age and ecological factors on fiber properties and analyzed how the fiber properties influence density and dimensional characteristics of the wood. Measurements of fiber properties were obtained from 451 specimens collected in the Guinean, Sudanian, and Sahelian zones in Burkina Faso, Niger, and Togo. The results indicate significant variations in average fiber parameters among the three climatic zones. This variability leads to an increase in the length, width, and thickness of the fibers along the north–south decreasing rainfall gradient. However, no noteworthy correlations were observed between cambial age and fiber properties, posing challenges in distinguishing between juvenile and adult wood. In terms of correlation, the analysis shows that fiber length has no effect on physical properties, but fiber width significantly influences basic density, wood shrinkage, and the fiber saturation point (FSP).