The use of e-assessment methods raises important concerns regarding the reliability and validity of these methods. Potential threats to validity include mode effects and the possible influence of computer-related attitudes. Although numerous studies have now investigated the validity of online assessments in noncourse-based contexts, few studies have addressed this issue in an educational context. The present study helps fill this research gap by investigating whether university students' computer-related attitudes and assessment mode preferences were related to performance on a course-based online assessment task. Overall, students' attitudes and preferences bore no greater relationships to performance on the online than offline module assessment tasks. This provides support for the validity of course-based online assessment methods and should help alleviate educators' concerns and encourage more widespread adoption of these methods, helping address the issue of their slow uptake to date. Suggestions for follow-up studies to corroborate and extend the current findings are offered.