Multiple chemical sensitivity (MCS) is a syndrome in which multiple symptoms reportedly occur with low-level chemical exposure. Several theories have been advanced to explain the cause of MCS, including allergy, toxic effects and neurobiologic sensitization. There is insufficient scientific evidence to confirm a relationship between any of these possible causes and symptoms. Patients with MCS have high rates of depression, anxiety and somatoform disorders, but it is unclear if a causal relationship or merely an association exists between MCS and psychiatric problems. Physicians should compassionately evaluate and care for patients who have this distressing condition, while avoiding the use of unproven, expensive or potentially harmful tests and treatments. The first goal of management is to establish an effective physician-patient relationship. The patient's efforts to return to work and to a normal social life should be encouraged and supported.