Open clusters are key objects to study the chemical evolution of the Galactic disk, but metallicities and detailed abundances are available for only a small fraction of them. We review here the current status of metallicity determinations. Open clusters are also perfect objects to test the chemical tagging method which intends to identify stars formed from the same molecular cloud. First results about this technique are presented, based on homogeneously derived chemical abundances for a large sample of stars in open clusters.