For the present study, an attempt has been made to study the effect of cypermethrin and fenvalerate on oxygen consumption of the freshwater hill stream fish, Garra mullya (Sykes). The fishes were exposed to 24 h lethal concentration (0.18 ppm) of cypermethrin, whereas 24 h lethal (0.26ppm) and two sub lethal concentrations (0.086 and 0.026 ppm) of fenvalerate for different time periods.