Cryphonectria canker, caused by Cryphonectria cubensis , has limited the development of new Eucalyptus plantations in tropical and subtropical regions. The pathogen is commonly found on Eucalyptus , but its occurrence on other hosts in the Myrtaceae has also been documented. In this study C. cubensis is reported as the causal agent of a serious canker disease on Tibouchina spp. ( Melastomataceae ) in Colombia. We used morphological studies, pathogenicity tests on Eucalyptus and Tibouchina , and a phylogenetic study using partial ribosomal DNA sequence data. This is the first record of C. cubensis on a host outside the Myrtaceae .