The objectives of this paper are threefold: (1) to assess the direction and magnitude of changes in agricultural productivity in Kenya in the last 25 years for five of the most important agricultural provinces in Kenya, with particular focus on the period since the initiation of agricultural policy adjustment in the 1990s; (2) to identify the major factors affecting changes in crop productivity; and (3) to identify cost-effective strategies likely to promote future agricultural intensification and productivity growth in Kenya's crop sector in the post-reform period.