We examine the clustering of attendance, illness, and accidental injury problems in a large unionized manufacturing plant using both quantitative and qualitative methods. We find that the distribution of workers into problem groups is related to 1) conflicts over seniority, 2) physical stressors and their influence on perceived desirability of certain kinds of jobs, and 3) organizational conditions and environments congenial to the development of distinct occupational "subcultures." We suggest that the case study approach we apply in this paper is critical to the design of programs of preventive intervention and complements the more commonly applied multiple-site and individually focused, survey approaches.