This article builds on previous studies concerning street-level bureaucracy (SLB), an expression coined by Lipsky to highlight the importance of the discretionary power that professionals in public agencies exercise during the implementation of laws, standards and guidelines. Connecting SLB theoretical framework and the new institutional organizational analysis, this article puts in how labour inspectors use their discretionary power when dealing with similar work irregularities in different organizational fields. Based on 9 months of participant observations and vignette interviews in a local office of the Italian Labour Inspectorate, the article aims to extend the range of both theories.