Abstract: Prevalence of fish disease has negative economic impact on aquaculture but the extent of this impact is not well documented. In order to quantitative economic impact of fish disease on rural freshwater aquaculture, a questionnaire survey and Participatory Rural Appraisal (PRA) tools were used in five districts of Bangladesh namely Mymensingh, Comilla, Jessore, Natore and Dinajpur. The study was conducted from January to December 2003. A total of 500 fish farmers were interviewed and 25 PRA session were conducted. The present study indicated that there were average economic loss of Tk.20,615/ha/year (US$344) to farmers from fish diseases which was equivalent to approximately 15% of the actual production. These losses varied among different districts and with different size of farms. The average loss as high as Tk.26,817/ha/year (US$447) was observed in Comilla district followed by Dinajpur Tk.23,412 (US$390), Mymensingh Tk.19,685 (US$328), Jessore Tk.18,177 (US$303) and Natore Tk.15,037 (US$251). Fish production also varied among different districts. The average highest (19.2%) loss of actual production was seen in Comilla district while the lowest (7.9%) were observed with farmers from Natore district. In general, small size farms suffered from highest average loss (19.6%) than the bigger size farms (14% for medium and 11.2% for large farm). Prevalence of fish disease varied among different districts with highest prevalence (18.2%) was seen in Jessore followed by Comilla (13.4%), Mymensingh (11.4%), Dinajpur (10.4%) and Natore (5.6%).