The goal of this study is to evaluate the use of positron emission tomography (PET) in evaluation of patients with peritoneal dissemination of carcinoma of appendiceal origin (PDA). Thirty-three patients with PDA, who had preoperative PET or PET/CT imaging, were analyzed. Using operative, pathology, and PET +/- CT data, presence or absence of disease in each abdominal quadrant was noted and the use of 18fluoro-deoxy-glucose (FDG) PET for each quadrant was evaluated. The mean age was 52, and there were 17 males; 58 per cent had low-grade lesions. PET was positive in only 35 per cent of cases overall (30 and 41% sensitivity for low-grade and high-grade, respectively). PET without CT sensitivity for low-grade and high-grade lesions was 21 and 8 per cent, respectively. PET imaging has limited use for patients with PDA. We do not recommend the use of FDG-PET for patients with PDA from cancer of the appendix.