Acne is a domain in which the technology and understanding of light/laser therapeutic procedures have advanced considerably. The aim of the paper was to revisit adjunctive physical treatments of acne, including light/laser treatments and photodynamic therapy. This review summarizes findings about such treatment modalities with particular emphasis on efficacy and safety. A number of laser/light-based modalities have been developed to meet the increasing demand for new acne treatments. The current devices correspond, on the one hand, to light-emitting diode therapy and, on the other hand, to the 532-nm potassium titanyl phosphate laser, the 585- and 595-nm pulsed dye laser, the 1450-nm diode laser, the 1320-nm Nd:YAG laser and intense pulsed light. Photodynamic therapy is also available. It is claimed that light/laser treatments might induce a faster response compared with the 1-3 months needed for response to traditional oral and topical treatments. In conclusion, pulsed dye laser shows efficacy in some patients with mild to moderate acne. The relative effectiveness compared with other treatments is unconfirmed; from the published information, evidence-based efficacy assessment of light/laser therapies in acne remains almost impossible.