Rice is the staple food in Bangladesh (Habiba et al., 2012). Haors are large bowl-shaped floodplain depressions in the North-eastern part of the country and produce 15.3% of the total rice (CEGIS, 2012). Flash flooding is sudden, localized flooding occurs by heavy rainfall over a short period within a catchment and produces a rapidly rising and fast-moving river flows (Kamal et al., 2018). Flash flooding damages rice production almost every year in Haors and challenges food security and economic growth of Bangladesh (Hossain et al., 2017). Enhancing agricultural innovation is considered a key process to ensure agricultural sustainability under complex climate-affected development conditions (FAO, 2018). To support agricultural innovation, strengthening and utilizing innovation networks are critical. An innovation network is defined as a heterogeneous group of actors who voluntarily contribute knowledge and other resources (e.g. money, equipment, land) to jointly develop or improve a social or economic process or product (World Bank, 2012). Nevertheless, there is anecdotal evidence about how Haor farmers have been utilizing their innovation network to adapt rice cultivation to flash flooding. Drawing on agricultural innovation and social network theory the research intended to examine the above question. The research examined two groups of Haor farmers, one who is directly supported by the Department of Agricultural Extension (DAE), which is the most significant public sector advisory service organization in Bangladesh and another who is not directly supported by DAE. Data were collected from randomly selected each 120 DAE- and non-DAE farmers of Shanir Haor in Sunamgonj district. The findings indicated that DAE-farmers had more formal and rule-based actors (e.g. DAE, research organizations) connected to their network, but non-DAE farmers had more informal and trust-based actors (e.g. relatives, input dealers) connected. DAE-farmers largely secured rice cultivation-related information from the formal actors and non-DAE farmers secured both information and inputs (e.g. seeds, harvesting machinery) from the informal actors. There was no significant difference of heterogeneity among the DAE- and non-DAE farmers in their innovation network. Due to dependency on and backstopping from DAE, DAE-farmers did not seek support from informal (e.g. relatives) and less frequent (e.g. harvesting labor) sources for flash flood adaptation. On the other hand, non-DAE farmers secured less information from formal actors. In addition, the exchange of information and resources between DAE- and non-DAE farmers were largely missing. The public sector extension service organizations (e.g., DAE) in Bangladesh need to take a holistic approach to build a network between the organizationally supported and non-supported farmers and encourage the interaction of both formal and informal actors in the innovation networks of Haor farmers.