Workers' compensation claim data for 1979 obtained from the Bureau of Labor Statistics' Supplementary Data System (SDS) were utilized to examine the demographic and occupational incidence of back strains/sprains among U.S. industrial employees covered by state compensation systems. These data were combined with estimated employment figures to provide incidence ratios, which allowed better approximations of industry- and occupation-specific risk. Industries found to have the largest incidence ratios were construction (1.6 claims/100 workers) and mining (1.5 claims/100 workers). Occupations with the largest ratios were miscellaneous laborers (12.3 claims/100 workers) and garbage collectors (11.1 claims/100 workers). The 285,468 compensation claims due to back strains/sprains filed in the 26 SDS states in 1979 suggest that back injuries continue to be a large and costly problem for U.S. workers and their employers.