Objectives: Patient satisfaction can provide a measure of service quality and serve as a predictor of health-related behaviors. Little is known about how patients' satisfaction with clinician-patient interactions affects their adherence to taking analgesics. The purposes of this study were to (1) investigate the predictors of patients' satisfaction with clinicians, and (2) examine whether patients' satisfaction with their clinicians can improve adherence to analgesic use. Design: A cross-sectional and descriptive design was used. Setting: Outpatient oncology clinic at a medical center in Taiwan. Participants: A convenience sample (N = 309) was recruited. Main outcome measures: The Medical Interview Satisfaction Scale 21 - Chinese Version, Short Version of the Barriers Questionnaire - Taiwan Form, Taiwanese version of the Morisky Medication Adherence Measure, and Interpersonal Physician Trust Scale - Chinese version, and Brief Pain Inventory Chinese Version. Results: Variables that could significantly predict patients' satisfaction were patient age and trust in clinicians, which together accounted for 33% of the total variance. Patients' satisfaction with their clinicians significantly predicted patients' adherence to medication use (OR = 3.10, P < 0.05). There was an interactive effect (OR = 0.12, P < 0.05) between patients' satisfaction and barriers to analgesic use. Correlation coefficients between barriers to analgesic use and patients' adherence are -0.52 (P < 0.001) and -0.13 (P = 0.20) in the higher satisfaction and lower satisfaction patients, respectively. Conclusions: Patients' satisfaction with their clinicians can have a positive effect on changing analgesics adherence behaviors when patients hold incorrect beliefs about analgesics. Patients' satisfaction has an important role in enhancement of analgesics adherence behaviors.