OBJECTIVES This study compared hypertension management in newly treated and previously treated (established) adult patients (≥18 years) with hypertension. METHODS A retrospective study was conducted using the GE Centricity electronic medical record database which contains ambulatory electronic health record data for over 7.4 million patients in the US. Patients were classified as newly treated hypertensives if they had no antihypertensive treatment within 24 months prior to the index date (date of the first anti-hypertensive prescription in 2006). Otherwise, patients were classified as established hypertensives if they received antihypertensive treatment during 24 months prior to index date. These two groups were compared to assess differences in comorbid conditions, proportion of patients treated per JNC-7 guidelines, distribution of index drugs, likelihood of achieving BP goal and changes in the antihypertensive therapy during 13 months follow-up period from the index date. RESULTS A total of 28,276 newly treated patients (mean age 58.6 years; 55.7% women) and 78,450 (62.1 years; 57.1% women) established patients were identified. Newly diagnosed patients had fewer comorbidities (mean number 0.74 vs. 1.85; p<0.001), less changes in anti-hypertensive medications (1.6 vs. 1.7; p<0.001), less likely to be treated per JNC-7 guideline (52.7% vs. 60.2%; p<0.001), and more likely to be treated on monotherapy at index (66.2% vs. 39.9%; p<0.001) than established patients. Among the newly diagnosed patients, ACE inhibitors (ACEi) (30.6%) and diuretics (19.2%) were the most commonly prescribed first-line treatments, while ACEi (22.3%) and the combination of ACEi and diuretics (9.2%) were more commonly prescribed in the established patients. After controlling for age, gender, race, comorbid conditions, baseline BP, adherence to JNC-7, newly diagnosed patients were 38% more likely to achieve BP goal at follow-up (p<0.001). CONCLUSIONS Newly treated hypertensive patients tend to be younger, with less comorbidities, more likely to be treated on monotherapy and achieve BP goal compared with established patients.