Over the last few years, cross-sectional imaging became clinically accepted for qualitative and quantitative analysis of left ventricular (LV) function. The results have an impact on diagnosis, therapy and follow-up, and some parameters even proved to be independent predictors of mortality. Besides well established cardiologic techniques, such as ventriculography and echocardiography, more recent radiologic techniques, especially magnetic resonance imaging (MRI) and multislice spiral computed tomography (MSCT), became accepted for imaging of LV function. Assessment of LV function with cardiac MRI is based on cine sequences. Over the last years, parallel imaging techniques, fast imaging with steady state free precession and real time sequences were successfully introduced. Further improvements were achieved by stress examinations and MR-tagging. Cardiac MSCT with retrospective ECG-gating allows for reliable determination of LV volumes. Assessment of wall motion is feasible but limited to some degree. Nevertheless, cardiac MSCT is a powerful alternative for patients with contraindications to MRI. Aim of this article is to review theoretical and technical aspects, opportunities and limitations of MRI and MSCT for functional imaging of the heart.