Fish anaesthesia is used to minimize handling stress and damage during harvesting, transportation, and during during surgical procedures. Through depression of cardiovascular and respiratory functions it causes significant changes in blood gases and pH. Here, we present the effects of Benzocaine, MS-222, and Aqui-S (Clove oil) on blood gases and haematological parameters of commercial sized (~1kg) stripped catfish (Pangasianodon hypothalamus) and the time course of recovery. Blood was taken by blind catheterization of dorsal aorta during anaesthesia, and regularly during the following 72 h recovery in aerated water. All anaesthetics caused rapid increases in pCO2 and lactate resulting in a sharp increase in pHe closely mirrored by pHi, as well as a marked rise in hematocrit, associated with increased RBC counts not altered RBC volume and elevated cortisol and glucose. All anaesthetics showed similar efficacy and blood parameters were normalized within 24 to 48h.