Prison work creates ethical challenges for which a training program was initiated for Dutch prison staff to foster their Moral Craftsmanship (MCS). The concept of MCS is not yet defined and operationalized in literature. This explorative study aims to 1) define MCS, 2) identify conceptual elements of MCS, and 3) develop a measurement tool for MCS. A document and literature study provided input for the definition and selection of conceptual elements related within DCIA policy documents, identifying three conceptual levels of (...) MCS: individual (cognition, attitude, and actions), team, and leadership. This first MCSQ consists of seventy-one items distributed across the domains: values and norms, judgment and reasoning, consultation, implementation, looking back, interactions, and leadership. We tested its usability via ‘think-aloud interviews.’ Validation of the current version of the MCS-Questionnaire and consensus among experts about what to include or exclude in the concept of MCS are needed for further development. (shrink)