A simple technique for the treatment of deep navicular and pedal joint infections in cattle is described. Under regional or local anaesthesia, a hoof-knife is inserted into the full depth of the discharging sinus and a large drainage area is created. A wooden block is glued to the sound claw and parenteral antibiotics are administered for four to six days. Of 64 cows treated between March 1986 and June 1989, 55 (86 per cent) recovered. The causes of failure and comparisons with other treatments are discussed.