Continued improvement in the results of laser treatment of port-wine stain (PWS), with reduction in scarring, will depend on the ability to use lasers to induce selective injury of only the abnormal blood vessels in the dermis. Photodynamic therapy (PDT), using an exogenous photosensitizing drug specifically activated by a certain wavelength of light, may be used to destroy selectively certain targets in the biological systems. The current study demonstrates, in the chicken comb animal model, that PDT using porphyrins and phthalocyanines activated by red light could be used to treat hypervascular dermal tissues.