Cytogenetic analysis of a recurrent periosteal chondroma revealed nonreciprocal translocations of both chromosomal segments 12q13-->qter, from one chromosome 12 to 7q32 and from the homologous chromosome 12 to 16q22. The remaining parts of the two chromosomes 12 formed a dicentric chromosome. This is the second reported chondroma with a 12q13-15 rearrangement, and changes of this chromosome region consequently seem to be nonrandom occurrences in chondromas.