e Molecular methods have been proposed as highly sensitive tools for the detection of Leishmania parasites in visceral leishmaniasis (VL) patients. Here, we evaluate the diagnostic accuracy of these tools in a meta-analysis of the published literature. The selection criteria were original studies that evaluate the sensitivities and specificities of molecular tests for diagnosis of VL, adequate classification of study participants, and the absolute numbers of true positives and negatives derivable from the data presented. Forty studies met the selection criteria, including PCR, real-time PCR, nucleic acid sequence-based amplification (NASBA), and loop-mediated isothermal amplification (LAMP). The sensitivities of the individual studies ranged from 29 to 100%, and the specificities ranged from 25 to 100%. The pooled sensitivity of PCR in whole blood was 93.1% (95% confidence interval [CI], 90.0 to 95.2), and the specificity was 95.6% (95% CI, 87.0 to 98.6). The specificity was significantly lower in consecutive studies, at 63.3% (95% CI, 53.9 to 71.8), due either to true-positive patients not being identified by parasitological methods or to the number of asymptomatic carriers in areas of endemicity. PCR for patients with HIV-VL coinfection showed high diagnostic accuracy in buffy coat and bone marrow, ranging from 93.1 to 96.9%. Molecular tools are highly sensitive assays for Leishmania detection and may contribute as an additional test in the algorithm, together with a clear clinical case definition. We observed wide variety in reference standards and study designs and now recommend consecutively designed studies. Visceral leishmaniasis (VL), or kala-azar, is a vector-borne disease that is caused by the protozoan parasites Leishmania donovani and L. infantum. The disease is transmitted to humans by the bite of infected phlebotomine sandflies. VL is a neglected tropical disease with an estimated 200,000 to 400,000 new cases and 20,000 to 40,000 deaths annually (1). More than 90% of all VL cases occur in Bangladesh, Brazil, India, Ethiopia, Sudan, and South Sudan. The clinical picture consists of fever, weight loss, fatigue, and general weakness; patients may present with enlarged lymph nodes, hepatomegaly, and splenomegaly. As VL is a fatal condition when left untreated and treatments have high toxicity, a diagnostic test that is both highly sensitive and specific is required. The gold standard for diagnosing VL is mainly the demonstration of parasites by microscopic examination of cultures of splenic aspirates. Splenic aspirates can be associated with hemorrhage, and the process should be carried out only with access to surgical facilities. For this reason bone marrow and lymph node aspirates are commonly taken for parasitological diagnosis. The specificity of these methods is high, but the sensitivity varies depending on the type of specimen, i.e., approximately 93 to 99% for the spleen, 53 to 86% for bone marrow, and 53 to 65% for lymph (2). In addition, the sensitivity and specificity of parasitological testi...