BackgroundIncreased attention has been dedicated to gender inequity at scientific meetings. This study evaluated the gender distribution of session leaders at cardiothoracic surgery national and regional meetings. MethodsThis is a descriptive study of the gender of peer-selected session leaders at 4 cardiothoracic surgery organizations' annual meetings from 2015 to 2019. Session leaders included moderators, panelists, and invited discussants. Data from publicly available programs were used to generate a list of session leaders and organization leaders. The primary outcome measure was the proportion of female session leaders at annual meetings. Descriptive analyses were performed, including the Cochran–Armitage trend test for linear trends of proportions. ResultsA total of 679 sessions over 20 meetings were examined. Of the 3662 session leaders, 480 (13.1%) were women. The proportion of total female session leaders trended positively over time from 9.6% (56 of 581) in 2015 to 15.9% (169 of 1060) in 2019 (P = .001). Among specialty topic sessions, female session leaders were distributed as follows: adult cardiac, 6.9% (81 of 1172); congenital cardiac, 10.8% (47 of 437); and thoracic, 23.2% (155 of 668). The proportion of female session leaders trended significantly only for thoracic sessions (20.6% [21 of 102] in 2015 to 29.2% [58 of 199] in 2019; P = .02). More than one-half of the sessions (57.4%; 390 of 679) featured all-male session leadership. ConclusionsWomen remain underrepresented in leadership roles at cardiothoracic surgery organizational meetings. This may deter female applicants and has implications for female surgeons' career trajectories; therefore, attention must be given to the potential for unconscious bias in leadership in cardiothoracic surgery.