Somatostatin (sms) receptors have been identified in carcinoids (c), so enabling their visualization with 111In-pentetreotide scintigraphy. The aim of this study was to evaluate if single photon emission computerized tomography (SPECT) can increase the sensitivity of sms receptor scintigraphy in the detection of abdominal c. 26 patients (pts) with a present, or previously operated, abdominal carcinoid were submitted to SPECT over the abdomen and multiple planar views after the injection of 111In-pentetreotide. Magnetic resonance imaging and computed tomography were also performed. In 19 pts abnormal sites of uptake were found by SPECT which localized 13 abdominal extrahepatic (in 11 pts) and 45 hepatic lesions (in 15 pts). No pathologic accumulation was seen in 7 pts in complete remission after surgery. Planar images visualized 7 abdominal extrahepatic (in 6 pts) and 26 liver tumor sites (in 10 pts), conventional procedures detected 5 abdominal extrahepatic (in 4 pts) and 36 hepatic lesions (in 10 pts). 111In-pentetreotide SPECT is more sensitive than planar scanning and conventional methods to detect abdominal c, and so may play a major role in the early and accurate mapping of tumour spread.