The study aimed at assessment of left and right ventricular functions, systolic and diastolic, global and regional in different groups of critically ill patients comparing both techniques of routine 2-D echocardiography including tissue Doppler study and myocardial nuclear imaging. A total number of forty-five critically ill patients were studied versus thirty-four healthy control group. The study showed the following: The control group showed heterogeneity between the different myocardial segments for systolic and diastolic velocities. Patients with coronary artery disease (CAD) showed dilated LV volumes as well as impaired ejection fraction by both techniques in relation to control. Impairment of regional LV systolic and diastolic functions as well as impairment of regional RV diastolic function. 22% of septic patients showed dilated LV volumes with impaired LV systolic function & 28% showed impairment of RVEF there was marked impairment of regional LV and RV diastolic functions versus the control group. Patient with chronic obstructive pulmonary disease showed marked impairment of LV and RV diastolic function, both global and regional in comparison to the control group. Both gated SPECT and 2-D echocardiographic techniques showed a good to excellent correlation regarding LV volumes & function.