Given the virtual disappearance of a land frontier due to rapid population increase, growth momentum in agriculture must be shifted from area expansion to land productivity increase. Land productivity can be increased by intensifying land use and/or by increasing yield per unit of crop area. Irrigation is the most strategic factor in enhancing land productivity, because it can contribute in both ways. This paper aims at confirming this fact by examining Philippines' experiences. A review of agricultural history of two rice villages reveals that the impact of multiple cropping under irrigation on the agricultural development at a village level is considerably higher than under rainfed conditions. The macro-level experience in the Philippines indicates that the government basically has dealt well in exploiting the irrigation potential of increasing land productivity by investing in irrigation infrastructure. However, the short run over-responsiveness in irrigation investment might have had an adverse impact upon government investment decision on the long run need of irrigation. The need to develop irrigation infrastructure both for enhancing production to meet the increasing food demand and for providing employment opportunities to the growing rural labor force will continue to be imperative in the near future.