<p>Tropical rainforests are critical biodiversity hotspots but are increasingly threatened by anthropogenic pressures that degrade their structure and ecological integrity. Monitoring environmental indicators of forest health is essential for assessing the effectiveness of management interventions. This study evaluated the effects of contrasting forest management regimes on stand structure, regeneration, and biodiversity in Kakamega Forest. Two regimes were assessed: the strictly protected Buyangu block under government management and the participatory forest management (PFM) block, subdivided into Isecheno (low disturbance), Ikuywa (medium disturbance), and Ileho (high disturbance), representing a clear gradient of management intensity and human pressure. We employed systematic transect surveys and plot-based sampling to quantify structural, regeneration and biodiversity indicators. Significant differences emerged across management regimes and zones. The Isecheno zone under PFM exhibited stronger forest structural condition, with a basal area (BA) of 89 ± 9 m²&#xa0;ha⁻¹ and tree species richness of 50 ± 2 species, compared to Buyangu’s lower richness (42 ± 3 species). In contrast, Ileho showed greater anthropogenic pressure, with logging levels far exceeding those in other sites (150 ± 20 stumps ha⁻¹), open canopy (50% closure), and reduced species richness (40 ± 1 species). Buyangu displayed the highest canopy closure (85%) and dead tree density (87 ± 15&#xa0;ha⁻¹), reflecting minimal human disturbance and a closed-canopy stand structure. These results demonstrate that integrating community engagement, robust environmental monitoring, and adaptive, site-specific strategies can improve forest health indicators while supporting conservation and livelihoods. The findings provide transferable lessons for tropical forests worldwide facing similar conservation challenges.</p>