Abstract: Declining agricultural production on some tropical farmland has prompted increased use of some inputs while continuous cropping prevails. This study analyzed the effect of intensive use of land on technical efficiency of farmers in Southwestern Nigeria. Data collected randomly from 303 selected farmers in 3 states. Results show that farmers from Osun State have the highest indices of intensification with respect to land use intensity, fertilizer use intensity and crop diversification. The Maximum Likelihood Estimates (MLE) of the frontier production function showed that the farmers are grossly inefficient. The parameters of chemical fertilizer and land areas are statistically significant (p< 0.01) while the coefficient of land area is with the highest elasticity of 0.265. Average technical efficiency is 24.78%, which portrays low agricultural productivity. Intensity of land use, at the present level reduces inefficiency possibly due to adoption of some soil conservation practices like application of fertilizer. The crop diversification parameter implies that as increasing crop specialization reduces farmers’ level of inefficiency. Use of mulching and organic manure significantly increases inefficiency. It was recommended that in the face of increasing land degradation, farmers’ access to effective soil conservation technologies must be increased in order to increase food production efficiency.