OBJECTIVES: To pool clinical trials of similar design to assess overall sensitivity and specificity of ioflupane I123 injection (DaTSCAN or ioflupane ((123)I)) to detect or exclude a striatal dopaminergic deficit disorder (SDDD), such as parkinsonian syndrome and dementia with Lewy bodies. DESIGN: Pooled analysis of three phase 3 and one phase 4 clinical trials. These four trials were selected because they were the four studies used for the US new drug application to the Food and Drug Administration (FDA). SETTING: Multicentre, open-label, non-randomised. PARTICIPANTS: Patients with either a movement disorder or dementia, and healthy volunteers. INTERVENTIONS: Ioflupane ((123)I) was administered. OUTCOME MEASURES: Images were assessed by panels of 3-5 blinded experts and/or on-site nuclear medicine physicians, classified as normal or abnormal and compared with clinical diagnosis (reference standard) to determine sensitivity and specificity. RESULTS: Pooling the four studies, 928 participants were enrolled, 849 were dosed and 764 completed their study. Across all studies, when images were assessed by on-site readers, ioflupane ((123)I) diagnostic effectiveness had an overall (95% CI) sensitivity of 91.9% (88.7% to 94.5%) and specificity of 83.6% (78.7% to 87.9%). When reads were conducted blindly by a panel of independent experts, the overall sensitivity was 88.7% (86.8% to 90.4%) and specificity was 91.2% (89.0% to 93.0%). CONCLUSIONS: In this pooled analysis, the visual assessment of ioflupane ((123)I) images provided high levels of sensitivity and specificity in detecting the presence/absence of an SDDD. Ioflupane ((123)I) imaging has the potential to improve diagnostic accuracy in patients with signs and symptoms of a movement disorder and/or dementia. TRIAL REGISTRATION NUMBER: NCT00209456.