Wood has been a fundamental material throughout human history due to its versatility and performance. However, wood's susceptibility to biodeterioration, primarily due to fungi and insects, poses significant challenges. This study assesses timber degradation by wood fungi and insects across Afghanistan's diverse climatic zones, including arid, temperate, and cold mountainous regions. To address this, a multifaceted descriptive method for data collection has been employed. The findings reveal distinct impacts of climatic conditions on wood degradation. In the arid climatic zone, 7.3% of species were affected by wood-decay fungi, with 5.5% attributed to brown rot and 1.8% to white rot. Additionally, 52.7% of degradation was caused by wood-stain fungi, with 25.5% due to sap-stain, 3.6% to mold, and 23.6% by chemical stain. Furthermore, 40% of wood decay in this zone was caused by insects, with termites accounting for 30.9%, beetles 3.6%, and carpenter ants 5.5%. In the temperate zone, 49.6% of species were affected by wood-decay fungi, with 34.7% due to brown rot and 14.9% to white rot. Moreover, 40.4% of degradation was attributed to wood-stain fungi, with 19.8% due to sap-stain, 12.3% to mold, and 8.3% to chemical stains. Insect activity in this zone accounted for 10% of wood decay, with termites affecting 1.7%, beetles 7.5%, and carpenter ants 0.8%. In the cold mountainous region, 69.2% of species were affected by wood-decay fungi, with 51.6% due to brown rot and 17.6% to white rot. Additionally, 30.8% of degradation was caused by wood-stain fungi, with 12.1% due to sap-stain, 13.2% to mold, and 5.5% by chemical stains. Notably, no insect activity was found in the cold mountainous climatic zone, as the severe freezing conditions deter insect presence. The results highlight the need for sustainable forestry practices and effective timber preservation strategies tailored to specific climatic conditions to mitigate the adverse effects of wood fungus and insect degradation.