Background: Diastolic function can be evaluated intraoperatively using transesophageal echocardiography. Aim: To study if intraoperative diastolic dysfunction is associated to a greater number of hemodynamic events during surgery and during the postoperative period. Material and methods: Patients with indication of intraoperative transesophageal echocardiography due to cardiovascular diseases were included in the study. Diastolic function was assessed measuring transmitral intraventricular filling delay and pulmonary vein flow. Patients were divided, according to diastolic dysfunction, in those with derangements in relaxation, pseudonormalization and restrictive patterns. Hypertension, hypotension, ST segment depression, alterations in myocardial contractility, pulmonary congestion and postoperative oliguria were recorded. Results. Fifty eight patients aged 68 +/- 12 years (39 males), were studied. Forty four had diastolic dysfunction. Intraoperative hypotension occurred in 82% of patients with diastolic dysfunction and 16% of patients without it, Likewise, hypotension and oliguria during the postoperative period were more common in patients with diastolic dysfunction. Conclusions. In this group of patients with cardiovascular disease. intraoperative diastolic dysfunction is a risk factor for hemodynamic instability (Rev Med Chile 2007; 135:1276 - 81).