In rehabilitative training and treatment of patients with cerebral palsy, return and maintenance of good muscle tonicity and suppression of tonic muscle spasm is crucial. However, an effective method that is reliable, simple, painless and noninvasive has yet to be reported. In the present study, 150 cerebral palsy patients were treated on their limbs and trunk with infrared diode low reactive-level laser therapy (LLLT) (810 nm. 60 mW and 100 mW, continuous wave) , The treatment sites were those normally associated with conventional therapies such as nerve block or acupuncture, and where muscular hyperspasm was particularly evident. In the majority of the patients, spasm was successfully suppressed by LLLT, with the notable exception of those patients suffering from severe joint contracture. Compared with conventional methodology, laser therapy has proved to be a simple, reliable and noninvasive method which enabled painless suppression of spasm. Another of the advantages of LLLT is that multiple repeated application is possible on any site selected by the physician, with an almost unlimited choice of treatment sites. The effect of LLLT lasted from one to several hours in patients with severe spasticity. Although it may be argued that this variable length of effect is one of the limitations of LLLT, the authors feel that LLLT is particularly useful as a supplementary or adjunctive therapeutic modality to improve the overall efficacy of physical rehabilitation and functional training in children with cerebral palsy.