['In contrast to standard donor retention strategies (e.g., mailings, phone calls, text messages), we developed a brief telephone interview, based on motivational interviewing principles, that encourages blood donors to reflect upon their unique motivators and barriers for giving. This study examined the effect of this motivational interview, combined with action and coping plan components, on blood donor motivations.', 'The design was to randomly assign blood donors to receive either a telephone-delivered motivational interview with action and coping plan components or a control call approximately 6\xa0weeks after their most recent donation. Participants completed a series of surveys related to donation motivation approximately 3\xa0weeks before telephone contact (precall baseline) and then repeated these surveys approximately 1\xa0week after telephone contact (postcall).', 'The sample was 63% female, included a majority (52.6%) of first-time blood donors, and had a mean age of 30.0 years (SD, 11.7\xa0years). A series of analyses of variance revealed that, relative to controls (n\u2009=\u2009244), donors in the motivational interview group (n\u2009=\u2009254) had significantly larger increases in motivational autonomy (p\u2009=\u20090.001), affective attitude (p\u2009=\u20090.004), self-efficacy (p\u2009=\u20090.03), anticipated regret (p\u2009=\u20090.001), and intention (p\u2009=\u2009<\xa00.001), as well as larger decreases in donation anxiety (p\u2009=\u20090.01), from precall baseline to postcall assessment.'] Does a brief motivational interview with action and coping planning components enhance motivational autonomy among volunteer blood donors?