A participatory strategies approach which involves employees in the planning and delivery of worksite health promotion programs was utilized in the 55 experimental worksites included in the national, NCI-funded Working Well Trial. According to study protocol, Employee Advisory Boards (EABs) were organized in each experimental worksite. This paper describes two substudies designed to develop and measure participatory strategies associated with the EABs in the Working Well Trial. Study 1 determined characteristics of the EABs, developed subscales and assessed the internal consistency of the scales. Study 2 used a confirmatory factor analysis to examine the structure of the developed questionnaire. The four subscales include: Autonomy/Independence, Management Involvement, Institutionalization/Commitment and Others Involvement. Results from Study 1 indicate that the four subscales of the 24-item instrument demonstrated strong internal consistency and three were sensitive enough to register differences by Study Center at the baseline. Study 2 results found that the EAB subscales again demonstrated good internal consistency, structural stability and acceptable sensitivity. An initial validity analysis was performed and yielded results which supported some but not all of the hypothesized associations. Implications for further refinement and application of this new instrument in worksite settings are explored.