Background and objective: An alternative approach in the treatment of acne vulgaris is photodynamic therapy (PDT) that uses light and aminolevulinic acid (ALA)-induced protoporphyrin IX (PpIX) production to eradicate Propionibacterium acnes found in acne lesions. PpIX formation is dependent on ALA percutaneaous penetration. In this study, to enhance ALA penetration and subsequent accumulation of PpIX, skin temperature was increased with radiant infrared (IR) prior to ALA-PDT application and compared to ALA-PDT alone in the treatment of inflammatory acne.