Oncogenes, along with the autocrine secretion growth factors, emerged as a unifying theme in the search for the molecular and cellular basis of malignant transformation. To investigate whether some of the oncogene coding sequences are philogenetically conserved, we performed hybridization experiments using well characterized c-myc, c-fos and c-ras oncogene probes to establish the sequence divergence in the genomes of different organisms. Our results indicate the c-myc, c-fos, and c-ras coding sequences exist in human, cow, monkey, rabbit, chicken, and yeast genomes. To the best of our knowledge this is the first report wherein a correlation among species in the oncogenes coding region has been established. The evolutionary implication of the present studies is discussed.