Background Decreased productivity at work is an important consequence of the presence of health problems at work. Methods The study population consisted of 2,252 workers in 24 different companies in The Netherlands it 2005-2006 (response 56%). Self-reported loss of productivity on the previous workday was measured on a 10-point numerical rating scale by the Quantity and Quality method. Logistic regression analysis was used to explore the associations between work demands, health problems, individual characteristics, and lifestyle factors with the occurrence: of productivity loss. Results About 45% of the workers reported some degree of productivity loss on the previous workday, with an average loss of 11%. Moderate and severe,functional limitations due to health problems (OR = 1.28 and 1.63, respectively) and lack of control at work (OR = 1.36) were associated with productivity loss at work with population attributable fractions of 7%, 6%, and 16%, respectively. Conclusion Productivity losses at work frequently occur due to health problems and subsequent impairments, and lack of control over the pace and planning of work. This will substantially contribute to indirect costs of health problems among workers. Am. J. Ind. Med. 52:49-56. 2009. (C) 2008 Wiley-Liss, Inc.