Occupational and environmental diseases frequently masquerade as routine medical disorders. Yet environmental factors rarely enter into the clinician's differential diagnosis. This article provides a sequence of steps that can be used by the practicing physician for detecting occupational diseases: Step 1: Routine screening questions for all patients (List of job titles? Exposure to fumes, dusts, chemicals, loud noise, or radiation? Temporal relationship of the chief complaint to activities at work or at home?). Step 2: Consideration of sources of exposure (workplace or home surroundings). Step 3: Identification and handling of the hazardous agent. Step 4: Follow-up, consultation, and resolution of the problem. Equipped with this approach, the clinician can play an important role in the detection and prevention of occupational- and environmental-related diseases.