The chimeric oncogene BCR/ABL, which is the product of reciprocal translocation between chromosomes 9 and 22, is a known molecular marker of chronic myeloid leukemia (CML), and is related to the major factors involved in leukemogenesis. Some previous studies have also reported the presence of this oncogene in peripheral blood cells of healthy individuals. In this study, we investigated the presence of BCR/ABL transcripts in peripheral blood of individuals aged 40 years or more without symptoms of CML. The presence of BCR/ABL transcripts was observed in 2 of the 30 individuals analyzed. The genesis of BCR/ABL transcripts and its presence in healthy individuals are topics of ongoing debate. The risks and biological implications of the presence of BCR/ABL transcripts in healthy individuals are challenging issues that remain to be elucidated.