OBJECTIVES: To determine the role of nuclear imaging (NI) in evaluating inconclusive cases with suspicion of infective endocarditis (IE). METHODS: Consecutive patients with an indeterminate diagnosis of IE who underwent labelled leucocyte scintigraphy (LS) or RESULTS: A total of 85 NI scans (28 FDG-PET/CT, 57 LS) from 76 patients were evaluated, of whom 48 (63.2 %) underwent only LS, 19 (25 %) only FDG-PET/CT, and 9 (11.8 %) both studies. Average age was 63.8 years (SD ± 18.5) and 51.3 % were women. Prosthetic valves were present in 15.8 % of cases, and intracardiac devices in 10.5 %. Among the 76 patients, 18 (23.7 %) had NI findings suggestive of IE. A total of 28 patients (36.8 %) were ultimately diagnosed with IE, 28.6 % of whom had confirmed infections by NI scans. Echocardiographic results had a low level of agreement with NI findings in those diagnosed with IE (kappa = -0.44). CONCLUSIONS: Nuclear imaging contributed to the diagnosis of IE in approximately 30 % of subsequently confirmed cases, which were initially classified as inconclusive by echocardiography. The low level of agreement between these methods underscores their complementary role in the diagnosis of IE, particularly in indeterminate cases.