Henoch-Schoenlein purpura is characterized by vasculitis of small vessels, particularly those of the skin, gastrointestinal tract, and kidney. Patients have characteristic purpuric skin rash plus all or some of the following: migratory polyarthralgias or polyarthritis, colicky abdominal pain, nephritis. Because until now there is no satisfactory treatment, we applied low level laser therapy (LLLT) in order to compare it with the classical therapy. Twenty-three children (2-15 years of age) have been treated at debut of the disease. They were randomly divided: group A (11 children) received LLLT; group B (12 children) was administrated classical therapy. Two GaAlAs diode lasers (670 nm and 830 nm) were used. The density of energy (4-8 J/cm2), irradiating frequency (2.4 Hz) was applied one session daily, using scanning technique under a special treatment protocol on cutaneous purpuric areas (20 sessions). The best results were obtained in laser group. Despite the complex medication, some patients from group B fell back into the former state after apparent improvement, and two children developed nephritis. The results could be explained by self-organization. LLLT is acting as a trigger factor causing certain systemic effects through circulating blood and a response of the entire immune system, by way of synergetic mechanisms.