Interphase cytogenetics using archival tissue samples is a straight forward approach to obtain “cytogenetic information” from the nuclei of solid tissue samples. It is the most important tool for investigating specific numerical chromosomal aberrations, chromosomal translocations, amplification of oncogenes, or deletion of tumor suppressor genes in archival tissue samples at a single cell level, since metaphase spreads cannot be obtained, obviously. Here, a collection of protocols for archival sectioned and mounted material as well as for extracted nuclei (from formalin fixed/paraffin embedded or cryofixed tissues) is presented.