The present study was designed to evaluate yoga's impact on blood pressure (BP) and quality of life (QOL) and on stress, depression and anxiety in patients with hypertension in a primary care setting. We conducted a multi-centre randomized controlled trial with follow-up after 12-week intervention completion. Adult primary care patients diagnosed with hypertension were randomly allocated to yoga or usual care. The intervention group performed a short home-based Kundalini yoga programme 15 min twice-daily during the 12-week intervention period. At baseline and follow-up, the participants underwent standardized BP measurements and completed questionnaires on QOL, stress, anxiety and depression. Data obtained from 191 patients (mean age 64.7 years, s.d. 8.4) allocated to yoga intervention (n=96) and control group (n=95), with a total proportion of 52% women, showed a significant reduction in systolic and diastolic BP for both groups (-3.8/-1.7 mm Hg for yoga and -4.5/-3.0 mm Hg for control groups, respectively). However, the BP reduction for the yoga group was not significantly different from control. There were small but significant improvements for the yoga group in some of the QOL and depression measures (P<0.05, Hospital Anxiety and Depression scale, HADS-D) compared with control. The findings of our study, which is the largest study from an OECD country (Organization for Economic Co-operation and Development) to date, do not support the suggestion from previous smaller studies that yoga lowers the BP. Further clinical trials are needed to confirm these findings. However, the yoga patients had other health benefits.