We recorded the usage of foot pumps during the post-operative period in 29 patients undergoing knee or hip arthroplasty and made 621 recordings. Effective utilisation of foot pumps was seen in 37.2% of cases. There was a gradual reduction in correct utilisation with each day that passed post-operatively (day 1, 60.4%; day 2, 48.8%; day 3, 28.8%; day 4, 21.4%; day 5, 23%). This gradual reduction was statistically significant (P=0.001) and mainly occurred between the second and third postoperative days. Effective usage was 60.2% overall at night and 36.4% during the day. Our results question the efficiency of foot pumps in deep venous thrombosis prophylaxis in the context of a true clinical setting.