A systematic review of randomised controlled trials (RCTs) was conducted to establish the effectiveness of low-level laser therapy as a treatment for venous leg ulcers. Wound-care journals, conference proceedings and electronic databases (including Medline and Cinahl) were searched up to October 1997 for RCTs comparing low-level laser therapy with sham laser, no laser, or non-coherent light of other wavelengths. In addition, companies who manufacture or distribute therapeutic lasers were contacted for any unpublished or ongoing studies. Results from searches were scrutinised by one reviewer to identify possible RCTs and full reports of these were obtained. Details of eligible studies were extracted and summarised using a data extraction sheet. Data extraction was checked by a second reviewer. Meta-analysis was used to combine the results of trials where the interventions and outcome measures were sufficiently similar. A total of four eligible RCTs were identified. Two compared treatment with laser therapy to sham or placebo laser treatment. One study compared laser therapy with ultraviolet therapy. The fourth was a three-armed study which compared the effects of laser therapy alone, laser therapy plus infrared light, and non-coherent unpolarised red light. The comparisons of laser therapy with placebo, and laser therapy with ultraviolet therapy, showed no significant difference between treatments with regard to ulcer healing rates. The comparison of laser with red light showed a significant increase in complete healing at nine months for the combination of laser and infrared light compared to non-coherent unpolarised red light. We have not found any evidence of the benefit of low-level laser therapy per se on venous leg ulcer healing. It appears that a combination of HeNe laser and infrared light may promote the healing of venous ulcers, however more research is needed.