Use of high-stakes exams in a course has been associated with gender, racial, and socioeconomic inequities. We investigated whether offering students the opportunity to retake an exam makes high-stakes exams more equitable. Following the control value theory of achievement emotions, we hypothesized that exam retakes would increase students' perceived control over their performance and decrease the value of a single exam attempt, thereby maximizing exam performance. We collected data on exam scores and experiences with retakes from three large introductory biology courses and assessed the effect of optional exam retakes on gender, racial/ethnic, and socioeconomic disparities in exam scores. We found that Black/African American students and those who worked more than 20 h a week were less likely to retake exams. While exam retakes significantly improved student scores, they slightly increased racial/ethnic and socioeconomic disparities in scores partly because of these differences in participation rates. Most students reported that retake opportunities reduced their anxiety on the initial exam attempt. Together our results suggest that optional exam retakes could be a useful tool to improve student performance and reduce anxiety associated with high-stakes exams. However, barriers to participation must be examined and reduced for retakes to reduce disparities in scores.