The current study aimed to determine the impact of sublethal concentrations of ash from the Durah Thermal Power Plant, mixed with polluted diet, on the biological aspects of Cyprinus carpio. The fish were exposed in the laboratory to diets containing 5, 10, 15, and 20 g/kg of ash. The LD50 values were 17.5, 11.71, 6.49, and 5.66 g/kg after 24, 48, 72, and 96 hours of exposure, respectively. The results showed a positive relationship between the percentage of mortality and the ash concentration in the diet, as well as the exposure duration. The percentage of deaths increased from 10 to 60% after 24 and 96 hours of exposure to a 5g/kg concentration. The LD100 was recorded at 15 and 20g/ kg, where 100% mortality occurred within 96 hours of exposure. It was concluded that the ash had a severe detrimental effect on the common carp, leading to environmental harm, especially when discharged directly in large quantities into water bodies.