In 18 patients, the liver volume during regeneration after partial hepatectomy for secondary tumours was estimated by single photon emission computerized tomography (SPECT). Hepatic weight index (HWI) was subsequently calculated to follow evolution of the regeneration as a function of postoperative complications over a 30-day period. In patients with postoperative complications the HWI curves initially rose progressively and either reached a plateau or declined thereafter. The same pattern of HWI evolution was observed in patients with tumour recurrence, which was diagnosed later. On the other hand, in patients without postoperative complications the HWI curves rose continuously. These findings showed that a regenerative response was not the same in patients with or without postoperative complications; whereas in patients with tumour recurrence it could additionally provide prognostic information.