Left ventricular diastolic dysfunction (LVDD) develops in the early stages of acromegaly. The purpose of this study was to identify LVDD analyzing by new echocardiograpic criteria as well as to evaluate determinants of the LVDD in acromegaly. This cross-sectional study examined 42 patients with acromegaly; 16 in active disease (AA) and 26 cured/ well controlled (CA), and compared them with 30 healthy controls (CG). Ventricular systolic and diastolic functions were studied by conventional and tissue Doppler imaging based on the E/Em ratio and myocardial performance index (MPI). Other clinical parameters possibly contributing to LVDD in acromegaly were also investigated. The prevalence of LV hypertrophy (33%) and LVDD (35.7%) were increased in acromegaly, however, there were no differences between the AA and CA groups. Acromegalic patients had higher LV volumes and LV mass, and septal E/Em ratio compared to CG, whereas LV ejection fraction and MPI were not different. The presence of acromegaly (r = 0.29, P = 0.013), diabetes mellitus (DM) (r = 0.41, P < 0.001), hypertension (r = 0.35, P = 0.002), and sleep apnea (r = 0.56, P = 0.003) were found to be correlated with LVDD, whereas duration and activity of acromegaly were not. In regression analysis, advanced age (OR: 8.53, P = 0.006) and DM (OR: 25.9, P = 0.007) were found to be independent risk factors for LVDD. The risk of LVDD according to new criteria increases in acromegaly. However, it seems to be related to the presence of DM and advanced age and is independent of disease duration and activity.