Cell depolarization is a pivotal event in the regulation of aldosterone secretion from adrenal zona glomerulosa cells by Angiotensin II and high plasma K+. The 2-pore domain potassium channels TASK3, TASK1 and TREK1 are important in the control of the membrane voltage of these cells. This study aimed at investigating the particular contribution of TASK3 potassium channels to the regulation of aldosterone production. TASK3-specific immunofluorescence was detected in zona glomerulosa cells and to less extent in zona fasciculata cells. The expression of TASK3 was sex-dependent with higher levels in male mice. The deletion of the TASK3 gene led to slight changes in the K+ sensitivity of aldosterone secretion in vivo. Similarly, small changes in the K+ dependence of aldosterone secretion were observed in ex vivo experiments using isolated adrenal glands. These data are suggestive for a role of TASK3 in the control of aldosterone secretion in mice and they could have implications for human disorders linked to pathological aldosterone secretion.