The importance of making online and distance education successful has been dramatically prioritized due to the COVID-19 pandemic. Student retention is a key performance indicator in online higher education. Evidence suggests that within online distance education the key to retaining students is to encourage an engaging and supportive online community. Online asynchronous forums are one method that has been employed to promote such engagement. This study investigated the relationship between online forum activity and student retention amongst 21 tutor groups on an Open University Level 1 module. It found that the volume of tutor group forum activity had a significant association with student retention (p<0.05 two-tailed, Pearson r=0.53), with student contributions having a greater impact on retention (p<0.01 two-tailed, Pearson r=0.628) than tutor contributions. Although tutor contributions did not appear to impact student retention directly the number of tutor and student posts were highly correlated (p<0.001, two tailed, Pearson r=0.86). Results indicate that asynchronous forums can be an effective tool in promoting student retention in an online distance learning environment. Important factors that impact on student retention within the educational medium of asynchronous forums are evidenced. The implications of these findings for educators are discussed. [Note: The page range (103-118) shown on the PDF is incorrect. The correct page range for this article is p103-117.]