Photodynamic therapy (PDT) with 5-aminolevulinic acid hydrochloride (ALA) is an established method for the management of AK. PD P 506 A (brand name Alacare®) is an approved medicinal product for the treatment of AK located on scalp and face. It is a self-adhesive, light-proof patch loaded with 5-ALA HCl and was developed for easy handling. AK located on arms, hands or trunk do not respond as well to ALA-PDT as AK lesions on the head do. It has been reported that occlusion during ALA incubation can improve clinical outcome after ALA-PDT for AK on hands and arms. We present the results of a first explorative pilot study involving 20 participants with a total of 145 treated (122 evaluable) AK lesions. The trial investigated the conduct of two ALA-PDTs within 1-2?weeks and involved all severity grades of AK. The model-based percentage of complete clearance on lesion-basis was estimated being 78.0 % (95 %-CI: [64.6 %; 87.3 %]), and the by-participant calculation (patient-based clearance) led to similar results (78.7 % with a 95 %-CI of [67.0 %; 90.3 %]). The treatment was well tolerated. Local reactions during ALA patch incubation were rare whereas nearly all patients showed the expected reactions during or after the illumination, primarily erythema and pain. The study results indicate that two PD P 506 A-PDT sessions 1-2?weeks apart are an efficacious treatment for AK on hands and arms. Especially mild but also moderate lesions responded very well to PDT treatment involving ALA incubation under occlusion.