In the past ten years environmental medicine has virtually exploded. Major instruments for the interdisciplinary environmental-medical diagnosis are history, on-site inspection, biomonitoring and ambient monitoring. Since the definitive diagnosis of an environment-related disease usually requires a joint evaluation of toxicological, somatic and psychosomatic findings, it is recommended that cooperation with an experienced center for environment medicine should be established early on. By doing so, an inappropriate diagnosis of unspecific environment-medical symptom complexes such as, e.g., multiple chemical sensitivity may be avoided. Such "diagnoses" may result in drastic, and for the patient and his family, often stressful, consequences.