Context: Adrenal venous sampling (AVS), with or without adrenocorticotropic hormone (ACTH) stimulation, is the test of choice to identify patients with a surgically curable subtype of primary aldosteronism (PA). Whether AVS with ACTH stimulation is more effective than AVS without ACTH stimulation remains controversial. Objective: To compare the effectiveness of AVS with ACTH stimulation and AVS without ACTH stimulation in patients with PA. Design: The Cochrane Library, PubMed, Embase, and Web of Science databases were searched to identify relevant articles. All cohort studies comparing the two techniques (AVS with ACTH stimulation and AVS without ACTH stimulation in a patient with PA) were included in the analysis. Results: A total of 14 studies met the inclusion criteria, and they were analyzed. AVS with ACTH stimulation did not significantly reduce the number of incorrect lateralization more than AVS without ACTH stimulation in patients with PA (OR: 0.76; 95% CI: 0.36, 1.59; P = 0.47). AVS with ACTH stimulation significantly reduced the number of unsuccessful cannulations of both adrenal veins more than AVS without ACTH stimulation in patients with PA (OR: 0.26; 95% CI: 0.17, 0.40; P , 0.00001). For subgroup analyses, it also significantly reduced the number of unsuccessful cannulations of left adrenal vein and right adrenal vein (OR: 0.14, 95% CI: 0.06, 0.33, P , 0.00001; and OR: 0.30, 95% CI: 0.12, 0.71, P = 0.007, respectively). Conclusion: AVS with ACTH stimulation can significantly reduce the number of unsuccessful cannulations, without significantly reducing the number of incorrect lateralization. Further studies are still needed to verify these findings.