Tissue Doppler Tei index is pointed to be more effective in the evaluation of global cardiac function than systolic and diastolic measurements alone in various heart diseases. This study was designed to assess the effect of cilnidipine on left ventricular function in hypertensive patients by using this index. A group of 40 hypertensives (mean age 55 ± 8 years, range: 35-65) and 16 controls (mean age 52 ± 9 years, range: 36-65) were included. Hypertensives were classified into non-left ventricular hypertrophy (NLVH) group (25 patients) and left ventricular hypertrophy (LVH) group (15 patients), and treated with cilnidipine for 2 months. Before and after treatment, the participants were examined by echocardiography. Tissue Doppler Tei index was calculated as diastolic time interval measured from end of late diastole to origin of early diastole (a′) minus systolic Sm duration (b′) divided by b′, that is Tei index = (a′ − b′)/b′. Thirty-seven hypertensive patients finished the treatment. Tei index was significantly higher in NLVH and LVH groups than in control group, and in LVH group than in NLVH group (0.44 ± 0.07 vs 0.28 ± 0.06, P < 0.001; 0.51 ± 0.13 vs 0.28 ± 0.06, P < 0.001; 0.51 ± 0.13 vs 0.44 ± 0.07, P < 0.05). After treatment, Tei index was significantly decreased (0.40 ± 0.11 vs 0.46 ± 0.10, P < 0.0001); systolic blood pressure and diastolic blood pressure were also decreased significantly. In conclusion, Tei index is impaired in hypertensives before development of ventricular hypertrophy and impairment is more prominent in hypertrophy. Cilnidipine can improve left ventricular function. Tissue Doppler Tei index is gaining importance in evaluating LV function after drug intervention in hypertensive patients.