The purpose of this study is to determine the clinical and immunologic status of trimellitic anhydride (TMA)-exposed employees who have had immunologic lung disease and who have been moved to lower-exposure jobs. In a case series design, 42 consecutive employees with TMA-induced immunologic lung disease were studied after they had been moved to low-exposure jobs for more than 1 year. Pulmonary symptoms were obtained by physician-administered questionnaire. Immunologic studies were performed using ELISA techniques. Spirometry and chest films were obtained annually. Employees with late asthma (n = 4), late respiratory systemic syndrome (LRSS) (n = 13), or both LRSS and asthma (n = 4) had improved symptoms, improved pulmonary functions, and lower IgE against TM-HSA. Fourteen of 21 employees with asthma had improved symptoms, improved pulmonary functions, and lower IgE against TM-HSA. The 7 who did not improve with transfer to low-exposure jobs did improve with transfer to jobs with no TMA exposure. There were no chest film findings in any group that were definitely related to TMA. Most individuals who develop TMA hypersensitivity syndromes improve with transfer to low- exposure jobs, but occasionally, individuals require transfer to a no-exposure job.