Three cases are summarized in which persistent chest wall pain, as well as elevations of creatine phosphokinase (CK) levels, occurred after exposure to chloropicrin vapor in an agricultural chemicals facility. Both the severity of the symptoms and the degree of biochemical abnormality appeared to follow a dose-response relationship. Myoglobinuria, on the other hand, was not found. Elevation of CK after chloropicrin exposure has not previously been reported and may represent low-grade rhabdomyolysis. Workups performed after symptomatic chloropicrine exposure should include CK-level determination.