Background Actinic keratoses are often treated by photodynamic therapy. However, the main side effect of this treatment is pain during and shortly after illumination. Objectives To evaluate, in an intra-individual study, whether the pain response differ in treatment of actinic keratoses in scalp and forhead, using branded methyl aminolevulinate (MAL) and aminolaevulinic acid (ALA). Materials and methods Patients with mild to moderate actinic keratoses on forehead and scalp were treated with methyl aminolaevulinate (MAL)-PDT and aminolaevulinic acid (ALA)-PDT on two similar areas of forehead and scalp. The pain response were measured using visual analogue scale ranging from 0 to 10 during the illumination and 30 min after the treatment. Results Fourteen patients completed treatment to MAL and ALA-PDT. We found no significant difference in pain intensity between MAL and ALA-PDT, neither during the treatment (p-value = 1) nor 30 min after the treatment (p-value of 0.19). Conclusions This intra-individual study demonstrate no significant difference between the pain response during PDT using methyl aminolevulinate and aminolaevulinic acid.