BACKGROUND: Hypertension is a global public health crisis. Poorly controlled high blood pressure is one of the major factors contributed to this crisis. As lack of treatment adherence is often considered the main reason for this failure, the Treatment Adherence Questionnaire for Patient with Hypertension (TAQPH) was developed. Since this questionnaire should be reliable and strongly valid to be used in clinics and research, this study was performed to test the reliability and validity of the TAQPH. METHODS: A cross-sectional study was conducted to validate the Persian version of TAQPH after using a modified forward/backward translation procedure. A total of 330 hypertensive patients were participated in this study. Construct and criterion validity, Cronbach¢s alpha, and test-retest reliability were used to validate the Persian scale. RESULTS: Data analysis showed that the scale had excellent stability (intraclass correlation = 0.95) and good acceptability of internal consistency (α = 0.80). The exploratory factor analysis (EFA) was meaningful but was not confirmed with confirmatory factor analysis (CFA). The scale score was correlated with Morisky Medication Adherence Scale (MMAS) score (Ρ = 0.27). CONCLUSION: In total, most of the psychometric properties of the 25-item P-TAQHP achieved the standard level and were sufficient to recommend for general use.