Twenty-six rabbits were subjected to various types of forepaw flexor tendon laceration. After two weeks the tendons were examined. Fibrosis was densest around the proximal stump of the divided profundus tendon. Double partial transverse nicks, designed to induce local ischaemia, caused no more fibrosis than a single longitudinal slit of the same length. Rendering the proximal stump ischaemic with a snare caused no increase in fibrosis. It was concluded that movement and tissue trauma are more important than ischaemia in determining the degree of fibrosis around the injured flexor tendon in the rabbit forepaw.