A matched case-control study was conducted for 72 cases of leukemia occurring among employees of four rubber and tire manufacturing companies during the period from 1964 to 1973, to determine if certain environmental exposures were related to the risk of developing leukemia. Earlier studies conducted in one company had shown an association of lymphatic leukemia with a work history of possible solvent exposure, and the results of the present study suggest that the association is weaker than previously described. However, recently acquired detailed environmental information reported elsewhere tends to support the initial finding at this company. Further studies are required to fully resolve this issue. A finding was the lack of association in the order three companies. In addition, lymphatic leukemia was found to be associated with work experience in general service jobs for the two larger companies from which a majority (89%) of the cases derive. Intervals from exposure death peaked at 27 to 38 years. No elevated risk for myeloid leukemia was found.