This investigation was designed to determine the release of fenbufen from suppositories and their bioavailability in rabbits. Suppositories containing fenbufen were made by the fusion method with Witepsol H-15, Wecobee and PEG 1540 base. Displacement value, weight variation, content uniformity, melting point and melting time were determined for preformulation of the fenbufen suppositories. The release rates were determined with the KP dissolution apparatus and with cellophane tube dialysis device and were increased in order of PEG 1540, Witespol H-15 and Wecobee. The bioavailabilities of fenbufen after rectal administration were also increased in order of PEG 1540, Witespol H-15 and Wecobee.