This study is an ex post analysis of the economic merit of Masagana 99 as a public investment. The analysis was carried out at the national and regional levels for the period CY 1973-74 to 1976-77. The economic returns from Masagana 99 were evaluated under four different assumptions as to what would have happened to paddy production if there had been no Masagana 99 Programme. The results of analysis have shown that Masagana 99 had contributed considerably to paddy production. At the national level, the increments in paddy production and the net returns from these increments were positive for all years and for all assumptions. However, only a few regions were responsible for the positive increments and positive returns. Possible changes to Masagana 99 that may result in further increases in efficiency of paddy production in the Philippines and a reduction in the financing costs of the scheme are discussed.