The objective of this study is to identify the contribution that selected demographic characteristics, health behaviors, physical health outcomes, and workplace environmental factors have on presenteeism (on-the-job productivity loss attributed to poor health and other personal issues). Analyses are based on a cross-sectional survey administered to 3 geographically diverse US companies in 2010. Work-related factors had the greatest influence on presenteeism (eg, too much to do but not enough time to do it, insufficient technological support/resources). Personal problems and financial stress/concerns also contributed substantially to presenteeism. Factors with less contribution to presenteeism included physical limitations, depression or anxiety, inadequate job training, and problems with supervisors and coworkers. Presenteeism was greatest for those ages 30-49, women, separated/divorced/widowed employees, and those with a high school degree or some college. Clerical/office workers and service workers had higher presenteeism. Managers and professionals had the highest level of presenteeism related to having too much to do but too little time to do it, and transportation workers had the greatest presenteeism because of physical health limitations. Lowering presenteeism will require that employers have realistic expectations of workers, help workers prioritize, and provide sufficient technological support. Financial stress and concerns may warrant financial planning services. Health promotion interventions aimed at improving nutrition and physical and mental health also may contribute to reducing presenteeism.