Cytogenetics is the preferred tool in the diagnosis of genetic diseases such as leukemia and detection of aquired chromosomal abnormalities, such as translocations, deletions, monosomies or trisomies, etc. The karyotyping is a set of procedures, in the scope of the cytogenetics, that produces a visual representation of the 46 chromosomes, paired and arranged in decreasing order of size, observed during the metaphase step of the cellular division (meiosis). The pairing is the procedure in the karyotyping process where the homologous chromosomes are paired according to dimensional, morphological and textural similarity criteria. This process is time consuming and is usually performed manually by experts. An automatic pairing algorithm is still an open problem. In this paper we present new contributions to solve the automatic pairing problem in the scope of the karyotyping process for leukemia diagnostic purposes. Besides the traditional features used to compute the similarity between ch...