Effect of anaesthetization on oxygen consumption with Benzocaine at a dose of 40.0 mg/l on the juveniles of Cirrhinus mrigala was observed using a cylindrical glass respirometer. The oxygen consumption of controlled fish increased from 2.124�0.13-5.949�0.53 mlO2/h with an increase in body weigh form 14.25�1.42-56.50� 4.93 g showed a reduction (p<0.001) of about 43% in 3h and 39% in 24h anaesthetization of Benzocaine respectively. The information is useful in calculation of oxygen requirement of this fish for their live transportation and other experimental purposes.