We investigated the feasibility of using hospital discharge diagnoses of ICD codes 506, 507, and 508, respiratory diseases from external sources, to identify occupational sentinel health events [SHE(O)]. Two hundred sixty-nine records were reviewed and 66 (25%) were incidents where the work-relatedness of the respiratory diseases was documented in the medical records. Twenty-six percent of the 269 records contained no exposure information. Sixty-four of the 66 occupational cases were from ICD codes 506.0-506.9, with the largest number classified as ICD codes 506.0 (bronchitis and pneumonitis due to fumes and vapors) and 506.3 (other acute and subacute respiratory conditions due to fumes and vapors). We conclude that surveillance of ICD codes in the 506 series, where 39% of the cases were secondary to occupational exposures, is a valuable component of a surveillance system for preventable occupational lung disease.