Research addressing the effects of cohort size on student success in asynchronous online discussions is sparse. As such, the following study attempted to determine an optimal student cohort size to enhance success and engagement within online discussions in general education courses at a large post-secondary university consisting of predominately adult learners. Experimental courses split mandatory discussions into one, two, or three cohorts to maintain a discussion size of no more than ten students per cohort per week. The effects of cohort size on student grade-point-average (GPA), withdraw rate, fail rate, and progression rate was evaluated in addition to effects on student satisfaction as measured by end-of-course surveys (EoCS). Results showed no significant difference in either student success or student satisfaction between courses with one, two, or three online discussion cohorts. Future online education research should focuses on upper division courses where students might benefit from smaller group discussions.d