BACKGROUND Impaired diastolic function and increased left ventricular mass are common findings in hypertensive patients and may occur early in the natural history of essential hypertension. In this study, we aimed to investigate the relationship between diastolic function parameters and coronary artery calcification (CAC) in hypertensive patients. METHODS The study was carried out on 128 asymptomatic hypertensive patients (58 women and 70 men). Diastolic function was evaluated by the mean ratio of peak of early (E) and peak of late (A) mitral inflow (E/A ratio), deceleration time, and isovolumic relaxation time. Patients were classified into two groups on the basis of the presence of CAC and were also divided into two groups on the basis of the presence of left ventricular hypertrophy. RESULTS The mean E/A ratio, deceleration time, and isovolumic relaxation time of CAC+ patients were 0.87±0.34, 143.93±29.11, and 87.86±16.34 ms, respectively, and 0.92±0.31, 140.80±27.90, 86.40±13.96 ms in CAC- patients, respectively. Diastolic function was not found to be related to the presence of CAC. The mean left ventricular mass index (LVMI) was determined to be 115.60±18.16 g/m in CAC+ patients and 104.93±29.54 g/m in CAC- patients, and the correlation between the presence of CAC and LVMI was statistically significant (P=0.019). A multivariate analysis showed that the E/A ratio was inversely related to age, blood pressure, pulse pressure, and LVMI (P<0.001) in CAC+ patients. In stepwise regression analysis, LVMI was the strongest determinant for the E/A ratio in CAC+ hypertensive patients (R=0.26, P<0.001). CONCLUSION Our results identify that diastolic functions are not affected by the presence of CAC in hypertensive patients; however, left ventricular diastolic function is impaired in the presence of left ventricular hypertrophy.