Topical 5-aminolevulinic acid (ALA) and various light sources have been used to treat actinic keratoses and acne. Many of these regimens have required long incubation times due to the penetration qualities of ALA. This study tested the effectiveness of ALA in producing erythema when applied for 10 minutes after 2 passes of microdermabrasion versus an incubation time of one hour without microdermabrasion. The areas were treated with a 595-nm pulsed dye laser at 15 J/cm2 or 22.5 J/cm2. Photographs were taken at 24 and 48 hours after the treatment. The data indicated consistent superior results with the use of microdermabrasion prior to the application of ALA for 10 minutes. It appears that incubation of ALA with microdermabrasion for 10 minutes is as effective as, or more so than, ALA applied alone for one hour in producing erythema.