background: photodynamic therapy is based on the association of a light source and photosensitizer in order to selectively destroy cells. objective: to evaluate the short and long-term effects, clinical response, and cosmetic outcome of the photodynamic therapy with 5-aminolaevulinic acid for non-melanoma skin cancer. methods: tthirty-four non-melanoma skin cancer - 19 bowen？s diseases and 15 basal cell carcinomas, were submitted to a single 6-hour topical and occlusive application of 20% 5-aminolaevulinic acid, and were later exposed to 630 nm diode laser single session. results: burning sensation during the session; erythema, edema and erosions in the first 72 hours; healing process after 4 weeks on average and excellent or good cosmetic results were observed. after 3 months, tumor-free rate was 91.2% whereas at 18 months,73.3%, similarly in bowen？s disease (72.2%) and basal cell carcinoma (75%). it was noticed a linear relation between the reduction in complete clinical response frequency and the increase in tumor dimension (p<0.001). conclusion: the 5-aminolaevulinic acid photodynamic therapy showed significant advantages such as minimally invasive for the treatment of multiple lesions in only one session or lesions in poor healing sites with superior esthetical outcome. the clinical and histopathological type/sub-type, the dimension and an appropriate follow-up must be considered to indicate topical 5-aminolaevulinic acid photodynamic therapy for non-melanoma skin cancer.