Cardiovascular diseases lead to high rates of mortality and morbidity. In many cases one important reason for a reduced heart function is the irreversible loss of heart muscle tissue due to cardiomyocyte death. However, one major problem in heart tissue regeneration is that most adult vertebrate cardiomyocytes are unable to proliferate. Thus, damaged heart tissue could not be repaired. Therefore, recombinant spider silk scaffolds were tested concerning their support of primary heart cells, because silk materials are biocompatible, biodegradable, hypoallergenic, non-inflammatory and show extraordinary mechanical properties, including high elasticity and strength. Previously, it could be shown that the poly-cationic spider silk protein variant eADF4(κ16) is more suitable for cardiac tissue engineering than the poly-anionic variant eADF4(C16). It was possible to attach neonatal rat cardiomyocytes more efficiently on eADF4(κ16) materials in comparison to non-cardiomyocytes, such as fibroblasts, endothelial cells or smooth muscle cells. The cardiomyocytes could be cultured on eADF4(κ16) substrates over a period of several days and retained their function, including contractility and beating behavior. Thereby, cell-to-cell communication and electric coupling occurred. Furthermore, cardiomyocytes responded properly to extracellular stimuli, such as pro-proliferative and pro-hypertrophy factors. The next steps will be the production, analysis and suitability of 3-dimensional spider silk scaffolds for cardiac tissue engineering.