The climate of Brahmaputra valley (located in the North-eastern Indian state of Assam) witnesses considerable changes with sub-tropical rain-storm atmosphere and has four well-defined seasons (monsoon, post-monsoon, winter and pre-monsoon) in a year. The state is experiencing extreme climatic events like erratic rainfall patterns (causing abnormally high floods) and drought-like situations in recent years, which adversely affects fish seed production thereby affecting pond aquaculture and fisheries enhancements in open-waters of the region. The present paper describes the major constraints faced by fish seed producers of the region because of extreme climatic events (abnormally high floods and prolonged dry spells) based on field studies in 27 fish seed production farms (randomly selected) located in three districts of Lower Brahmaputra Valley Zone of Assam, India. Primary data on different aspects of constraints faced by the fish seed producers because of extreme climatic events were collected and analysed. Rank Based Quotient values were calculated, based on ranks given by the fish seed producers for each constraint to prioritize them. Dominant constraint related to abnormally high floods faced by the fish seed producers was ‘loss of brood stock’ (Rank based quotient = 99.1) whereas the least important constraint was ‘entry of weeds/macrophytes’ during floods (Rank Based Quotient = 25.5). Constraints related to drought-like situations ranged from the least important ones like ‘low milt production of male brood fishes’ that had the lowest value (12.5) to the over-arching constraint of ‘inadequate water depth in fish ponds’ during pre-monsoon and prolonged dry spells (Rank Based Quotient = 100.0). Adaptive strategies developed by fish seed producers of the study region to overcome the major constraints have been outlined in the paper. The need for developing improved risk management at macro-level through appropriate policy support to fish seed producers in the fish-deficit region and suggested policy support measures for ensuring sustainability are discussed.