Potassium permanganate (KMnO4) is a widely used freshwater aquaculture chemotherapeutant for the treatment and prevention of waterborne parasitic and fungal diseases. The aim of this research was to determine its effects on some biochemical parameters of the widely consumed African catfish, Clarias gariepinus. C. gariepinus were exposed to a sublethal concentrations (0.0, 2.0, 6.0 and 10.0mg/L) of potassium permanganate for 12, 24, 48, 96 and 192 h adopting the static renewal bioassay technique and subjected to blood and plasma analyses. Blood samples were obtained from the caudal circulation and plasma was obtained from blood samples by centrifugation and analyzed spectrophotometrically for plasma biochemistry using Randox kits. Significant dose-dependent increases were recorded in plasma glucose, total plasma protein, plasma cholesterol and plasma triglyceride. The results suggest that potassium permanganate can negatively affect the fish, causing various disturbances in its health and wellbeing. It is hereby recommended that potassium permanganate widely used in controlling external fungal, bacterial and protozoan infections of fish should not be used indiscriminately
