PurposeWe sought to conduct a systematic review to determine the diagnostic test accuracy of point-of-care ultrasound (POCUS) for the specific etiologies and subtypes of shock.MethodsWe searched MEDLINE, Embase, and the grey literature for prospective studies in adult populations with shock. We collected data on study design, patient characteristics, operator characteristics, POCUS protocol, and true and false positives and negatives, and assessed the risk of bias.ResultsWe found 18 eligible studies with a total of N = 2,088 patients. The pooled sensitivity and specificity of POCUS for determining shock subtype were 90% (95% confidence interval [CI], 81 to 95) and 95% (95% CI, 90 to 97) for hypovolemic shock, 95% (95% CI, 84 to 98) and 98% (95% CI, 97 to 99) for cardiogenic shock, 78% (95% CI, 69 to 85) and 97% (95% CI, 94 to 99) for distributive shock, 94% (95% CI, 85 to 97) and 99% (95% CI, 98 to 100) for obstructive shock, and 85% (95% CI, 77 to 91) and 98% (95% CI, 91 to 100) for mixed shock (all low to moderate quality evidence). The pooled sensitivity and specificity of POCUS for determining specific shock etiologies were 78% (95% CI, 18 to 98) and 96% (95% CI, 87 to 99) for sepsis, 92% (95% CI, 71 to 98) and 99% (95% CI, 83 to 100) for pulmonary embolism, and 100% (95% CI, 69 to 100) and 100% (95% CI, 98 to 100) for cardiac tamponade. The quality of the evidence ranged from very low to moderate.ConclusionsOn the basis of very low to moderate quality evidence, POCUS may perform better at ruling in shock subtypes and specific shock etiologies than ruling them out. Point-of-care ultrasound is a promising tool for the diagnosis of shock.Study registrationPROSPERO (CRD42020160001); first submitted 1 December 2019.