This paper aims to analyze adoption patterns and extent of adoption of new generation modern varieties (MVs) of rice focusing on household survey of 1900 farmers in 19 stress-prone rainfed districts of India, Bangladesh and Nepal. The data for this study was collected as a part of broader socioeconomic baseline studies of IRRI led STRASA project in South Asia. Adoption patterns and factors determining adoption of newer generation MVs and their farm level yield effects and profitability were assessed across sample households. The findings showed that a large proportion of farmers were adopting both old (released before 1990) and new generation (released after 1990) MVs in major portion of their rice area. However, newer generation MVs released after 1990s were adopted in less proportion of their rice farms in the wet season when rice production is often affected by climatic stresses such as drought, flooding and coastal salinity. The factors responsible for the low adoption in the rainfed stress-prone environments are attributed to the limited yield superiority and low profitability of the new generation MVs. This study also employed econometric analysis using Probit and Tobit models to study the factors determining adoption of new MVs using data from both plot and household levels. The findings showed that both plot and farm-specific variable such as differences in the endowment of land type was the key determinant of new MV adoption across households in most of the locations. Other farm and farmer specific socioeconomic and institutional variables were significant only in few locations. Future rice R&D programs, therefore needs to take into consideration of farmers‟ endowment of land types including other important variables for micro-level targeting of new generation MVs suited to rainfed less-favoured environments.