This study aimed to evaluate drug utilization of anti-hypertensive medications in a tertiary care teaching hospital. In this study, a cross sectional study was conducted in hypertensive who visited General Medicine department in a tertiary care teaching hospital, during the period of August, 2013 to August, 2014. 1407 new prescriptions were analyzed according IP/OP numbers of rational drug utilization by using WHO Core drug use indicator and WHO ATC/DDD metric systems. A total of 10,638 drugs were prescribed. Of this, (20.4%) antihypertensive, (45.21%) angiotensin converting enzyme (ACE) inhibitors, 24.0% beta blockers, 17.7% calcium channel blockers, 11.4% diuretics, 1.5% angiotensin II receptor antagonist, 7.56 ± 2.76 mean number of drugs prescribed/prescription, 34.9% free drugs were prescribed from Tamil Nadu Standard Treatment Guidelines (TNSTG), 65.05% were prescribed from Rajah Muthaih Medical College Hospital Drug List (RMMCH). 14.9% antibiotics, 46.76% Injections, mean 13.8 min consultation and mean 147.48 seconds dispensation, both conceived as good patient care, 89.1% drugs actually dispensed, 87.1% drugs adequately labeled, 38.3% subjects had adequate knowledge on frequency of taking medicines. A total (n=82) subjects were admitted in the internal ward and average length of hospital stay was found to be 10.33 ± 6.66 and overall antihypertensive drug consumption was found to be 122.07 DDD/100 Bed-days. The present study finding showed, ACE inhibitors were most frequently prescribed and amlodipine was highest consumed drug in the internal ward. Many of the prescriptions were observed rationally, even though further more improvement is needed in drug prescribing practices for hypertensive study population.