Malignant mesothelioma (MM) is strongly associated with asbestos exposure. Measurement of soluble mesothelin-related protein (SMRP) levels in the serum may prove valuable as an adjunct to current tests for the diagnosis of MM and for monitoring MM patients for the early detection of disease recurrence. SMRP measures also may be useful in an overall screening program for MM because early results show that some individuals have elevated levels 1 to 4 years before symptom development. Although individuals with occupational and nonoccupational asbestos exposure are justifiably concerned about their risk of developing MM, consideration must be given to the complex issues surrounding screening for this disease, and a more substantial evaluation of the SMRP marker must be undertaken before deciding to promote a screening program.