Washington State's workers' compensation claims filed in 1984 and followed through 1988 contained 11,356 claims for occupational disease and 178,927 claims for occupational injury. There was a higher rate of rejection (18% v 4%) and resource utilization (14% v 5%) for occupational disease when compared to occupational injury. The factors most predictive of rejection included the specific disease category and the provider frequency of filing. Development of diagnostic guidelines would aid health providers in identifying and properly characterizing occupational diseases.