Direct surveys of groups of workers can provide valuable occupational health surveillance data, but this requires consistent collection of data. As part of efforts to improve the standardization of such methodology, NIOSH is developing a standard occupational health questionnaire. This questionnaire will be designed to collect demographic and occupational history information in addition to information about the presence of a spectrum of work-related conditions. The questionnaire will have a modular structure and will consist of a core questionnaire and a series of condition-specific modules.