Path analysis was used to examine sex differences in motivation for repeat donation among experienced blood donors. Results confirm the importance of constructs from the Theory of Planned Behavior (e.g., donation attitude, subjective norm, personal moral norm, and donation self-efficacy) and of prior donation experience (e.g., vasovagal symptoms, overall satisfaction) as significant predictors of donation intention. Importantly, the findings also indicate that a consideration of sex differences in donor motivations results in a better prediction model and suggests a framework of possible avenues where interventions could be expected to improve donor return rates.