population. Design and method: From a clinical database all adult Chinese patients aged >18 years were prescribed a thiazide diuretic from the public health care sector in one large Territory of Hong Kong during January 2004 to June 2007 and attended at least twice for antihypertensive drug refill were included. Medication Possession Ratio, an internationally recognized metric to measure drug compliance for each patient, was used with a level >80% defined as compliant. We used binary logistic regression analysis to evaluate the factors associated with good compliance while controlling for patients' age, gender, payment status (fee-payers vs. fee-waivers; as a proxy measure of socioeconomic status), clinic type (general outpatient clinic vs. family medicine specialist clinic vs. staff clinic), district of residence, visit type (new vs. follow-up visit), number of comorbidities and the calendar years of drug prescription. Results: From 8,551 eligible patients, 84.5% were compliant (defined as MPR>80%). Fee payers (adjusted odds ratio [aOR] 1.28; 95% C.I. 1.12– 1.46, p<0.001) and follow-up visitors (aOR 2.47, 95% C.I. 2.13–2.87, p<0.001) were significantly associated with better antihypertensive compliance. Patients' age, gender and number of comorbidities were not significant associated factors. Conclusions: Patients who were newly prescribed thiazide diuretics and those with poorer socioeconomic status were more likely to be non-compliant to antihypertensive therapies. Closer monitoring and more intensive compliance-enhancing strategies should be targeted towards these patients to enhance clinical outcomes.