Background: The pharmacist-patient relationship has evolved over recent decades and the development of clinical pharmacy requires pharmacists to take patient-centered responsibilities. This requires a specific set of skills, such as patient-centered communication. Evaluation of students' competencies in patient-centered communication is challenging in academic settings and complementary assessment methods may be designed in order to overcome the limits of traditional preceptors' ratings or objective structured clinical examination (OSCE). There is increasing interest in a more active patient role in healthcare professional education and there are very few reports about patient-led education in pharmacies. Thus, the objective of this work was to implement a patient-teaching workshop and to assess its impact on pharmacy students' competencies in patient-centered communication. Methods: The workshop was developed in collaboration between four patients, a senior clinical pharmacist and a lecturer in education sciences and implemented in the hospital pharmacy residency program. The main course objective was acquiring the three competencies of the Calgary-Cambridge guide to the medical interview: (i) building a relationship, (ii) conducting structured interview and (iii) gathering information. The learning process integrated: working on participants' perception of pharmacists-patient communication, a first simulated interview, didactic learning and a second simulated interview. After simulated interviews, patients and peer residents assessed learner's performance with a competency chart and provided individual feedback. Assessment methods included comparisons between the first and second interview scores and an anonymous post-course survey. Results: Forty-seven residents and 19 patient teachers attended the session. Competency scores were higher after the second interview in all three competencies as rated by both patients (+ 25%) and peer residents (+ 29%). Residents expressed a high satisfaction and reported learning about conducting interviews and soft skills contributing to the development of a relationship with patients. "The involvement of patients" was expressed as most appreciated in the majority of the evaluation charts (87%) and the residents valued the importance of collaborative and interprofessional learning during the workshop. Three themes emerged: (1) patients' expertise, (2) reliability and (3) relationship, which underlined that the students estimated the patients were credible sources of information in this pedagogical context. Conclusion: This patient-teaching approach improved patient-centered competencies of pharmacy residents and promoted partnership between patients and pharmacy students.