Objectives: To assess the impact of passive and active promotional strategies on patient acceptance of medication therapy management (MTM) services, and to identify reasons for patient acceptance or refusal. Methods: Four promotional approaches were developed to offer MTM services to eligible patients, including letters and bag stuffers ("passive" approaches), and face-to-face offers and telephone calls ("active" approaches). Thirty pharmacies in a grocery store chain were randomized to one of the four approaches. Patient acceptance rates were compared among the four groups, and between active and passive approaches using hierarchical logistic regression techniques. Depending on their decision to accept or decline the service, patients were invited to take part in one of two brief telephone surveys. Results: No significant differences were identified among the four promotional methods or between active and passive methods in the analyses. Patients' most frequent reasons for accepting MTM services were potential cost savings, review of how the medications were working, the expert opinion of the pharmacist, and education about medications. Patients' most frequent reasons for declining MTM services were that the participant already felt comfortable with their medications and felt their pharmacist provides these services on a regular basis. Conclusion: No significant difference was found among any of the four groups or between active or passive approaches. Further research is warranted to identify strategies for improving patient engagement in MTM services.