The acute haemodynamic and metabolic repercussions of total venous inflow occlusion were evaluated in six normal dogs, each of which underwent two four minute occlusions and one eight minute occlusion at normothermia. A further three dogs underwent a single eight minute period of occlusion and were allowed to recover from anaesthesia. Total venous inflow occlusion was well tolerated by all animals. They remained in sinus rhythm at the completion of occlusion, and unassisted haemodynamic recovery occurred rapidly. Recovery was quicker after four minutes than after eight minutes. There was no clinically detectable neurological impairment in three dogs which were allowed to recover.