Rupture of the tendons of both peroneus longus and peroneus brevis results in considerable disability. We have performed transfer of flexor digitorum longus (FDL) to peroneus brevis in two patients with lateral instability of the hindfoot due to chronic transverse tears of both tendons for which end-to-end repair was not possible. Both patients had excellent function when reviewed after eight and six years, respectively, with no symptoms. CT showed a normal appearance of the FDL in both patients, but the peroneal muscles looked abnormal. Transfer of the FDL provides a reliable solution to lateral instability of the hindfoot resulting from loss of function of both peronei