This paper describes the development and psychometric evaluation of scales measuring the dimensions of 'will' (belief, confidence, prior action and desire) for heart health promotion specifically and health promotion in general at both an individual and organizational level. Content validity was established through a series of focus groups and expert opinion assessments, based on a compilation of capacity-assessment instruments developed by other provinces involved in the Canadian Heart Health Initiative and the literature. Psychometric analyses of questionnaire data provided empirical evidence of the construct validity and reliability of the 16 individual and 21 organizational level 'will' scales. A series of principal component analyses assisted in verifying the unidimensionality of the measures and all scales yielded high internal consistencies with Cronbach's alpha coefficients ranging between 0.73 and 0.96. These measures can be used by both researchers and practitioners for assessing the 'will' to promote heart health specifically and health promotion in general.