Wawira KM, Thenya T. 2017. Assessment of indigenous tree species conservation in subsistence agricultural production systems: A case study of Lari Sub-county, Kiambu County, Kenya. Asian J For 1: 55-63. Conservation of indigenous trees is important because they regulate nutrients, build organic matter of topsoil, fix nitrogen and create habitat for beneficial soil micro-organisms. Subsistence agriculture is characteristic land use feature in Kenya especially in the humid and sub-humid regions. Often indigenous trees are cleared to pave way for farming and replaced with exotic trees. The results showed that various indigenous tree species were retained on-farm including species like Acacia abyssinica, Olea europaena, Ficus thonningii, Brachylaena hutchinsii, Allophylus abyssinicus, Vitex keniensis and Prunus africana. The remnants of indigenous trees were scattered on farm with 57.4% along the boundary, 38.9% around the homestead 2.6% inside the farm and on riverine areas 1.1%. Soil conservation, timber, and fuel wood, were given as the main reasons for conserving indigenous tree species on the farm. While the main reason for planting exotic on farm includes economic purposes like income, fuel wood and decreased land sizes, according to 60% of respondents. Overall the findings indicate significant decrease of indigenous trees conservation on farm due to longer maturity span compared to exotic trees. There is need to promote alternative uses of indigenous trees as well as reinforce the 10% tree cover to include that 2% of the latter should be indigenous in nature.