In a consistent effort to raise productivity and unlock the unrivaled economic and social potentials of the agricultural sector, the Senegalese government, as many of its African counterparts, has designed and implemented heavy subsidy programs, some of which targeting the use of inputs. This paper assesses the potential impact of fertilizer subsidy on farmers' productivity. Using a farm-level survey data from the Senegal River Valley, the paper develops a two-part methodology: first the data envelopment analysis is used to generate efficiency scores, and then the latter is related to the subsidy program using an endogenous treatment-regression model that accounts for potential endogeneity and self-selectivity issues. The results indicate that the subsidy programs seem to be working, as they appear to be associated with increased efficiency. The results also suggest ways to improve the effectiveness of the subsidy program as well as additional policy options to further unlock the agricultural potentials.