The study was conducted to estimate the degree of heterosis or hybrid vigor in production traits and ranging ability of chickens under organic management system. Five genotypes were evaluated, namely: two strains of Philippine native chickens Banaba (BB) and Paraoakan (PP), Sasso (SS), the two crosses Banaba x Sasso (BS) and Paraoakan x Sasso (PS). Principles of organic production of chickens were applied whereby free-range feeding was part of the standard operating procedure. The findings showed favorable effects of crossing the Philippine native chickens with improved breeds like Sasso on the overall performance of the birds. It was observed that heterosis was substantial both in the productive traits and ranging ability when either BB or PP was crossed to SS. For body weight, heterosis was found to be as high 18.2 and 25.8 % in BS and PS, respectively. Heterosis in feed conversion ratio was as high as -27.8 and -19.8 % for BS and PS, respectively, indicating efficient feed conversion for the crossbreds. Heterosis for ranging ability went as high as 20.8 and 26.7 for BS and PS, respectively, which signified good adaptability of the crossbreds to the organic management system.