Cardiovascular morbidity and mortality are increased in patients with primary hyperparathyroidism (PHPT). We aimed to evaluate left ventricle systolic and diastolic functions with tissue Doppler imaging (TDI) and strain and strain rate echocardiography in patients with PHPT. Thirty-one patients with PHPT and 29 healthy controls were evaluated with conventional and pulse Doppler echocardiography, TDI and strain and strain rate echocardiography. Myocardial performance index (MPI) was calculated. Strain and peak systolic strain rate in mid and basal segments of lateral, anterior, inferior, and septal walls of left ventricle were determined. TDI showed similar late diastolic myocardial peak velocity in two groups. Peak systolic mitral annular velocity, early diastolic myocardial peak velocity, and ratio of early to late diastolic myocardial peak velocity were lower in PHPT patients (p = 0.01, p<0.001 and p<0.001, respectively). MPI calculated by TDI was 0.53 +/- 0.15 in PHPT group and 0.44 +/- 0.09 in control group (p = 0.013). Strain values were lower in mid and basal segments of septum, lateral and anterior walls, and basal segment of inferior wall in PHPT patients. Mean systolic strain was -20.88 +/- 2.30 and -24.25 +/- 2.13 in PHPT patients and control group, respectively (p<0.001). Mean strain rate was lower in PHPT patients compared to control group (-1.38 +/- 0.19 vs -1.57 +/- 0.25) (p = 0.002). Patients with PHPT, but no cardiac symptoms or documented cardiovascular disease, have subclinical systolic and diastolic myocardial dysfunction. Evaluation of these patients with TDI and S and Sr echocardiography in addition to conventional echocardiography might be valuable to detect subclinical cardiac involvement.