Like many other South and Southeast Asian countries, different national and international organizations are actively promoting integrated rice-fish farming system (IRFFS) as a potential technique to alleviate poverty, food and nutrition insecurity in different parts of Bangladesh, since 1990s. However, little rigorous empirical research exists on the determinants of adoption and welfare impact of such technologies, particularly in marginalized people's settings. This article addresses this research gap, using the case of indigenous small-scale IRFFS farm households cross-sectional survey data from Northern and Northwestern Regions of Bangladesh. It employs double hurdle model for determining the factors affecting IRFFFS adoption and intensity of adoption in the first stage and propensity score-matching (PSM) method to analyse the causal impact of IRFFS adoption on welfare of marginalized indigenous farm households in Bangladesh in the second stage.