A 65-year-old man with subfoveal choroidal neovascularization (CNV) underwent photodynamic therapy (PDT). Despite the sequential treatments, the CNV grew larger and finally penetrated the retina. Vitreous adhesion was observed at the edge of the supraretinal fibrotic tissue. The case highlighted the possible unexpected side-effect of PDT. The upregulation of the vascular endothelial growth factor or the enhanced vitreous traction was considered to be responsible for the event.