Nuclear physics plays a crucial role in various aspects of core-collapse supernovae. The collapse dynamics is strongly influenced by electron captures. Using the modern many-body theory, improved capture rates have been derived recently with the important result that the process is dominated by capture on nuclei until neutrino trapping is achieved. Following the core bounce the ejected matter is the site of interesting nucleosynthesis. The early ejecta are proton-rich and give rise to the recently discovered νp-process. Later ejecta might be neutron-rich and can be one site of the r-process. The manuscript discusses recent progress in describing nuclear input relevant for the supernova dynamics and nucleosynthesis.