Professional services such as educational services, are increasingly managed and optimized in order to improve performances. Performances of students, teachers and school (boards) are measured and evaluated. Increasingly, rules and systems focus on outputs and control. Consequently, the ‘freedom’ of professionals such as teachers is reduced, or is perceived and felt to be reduced. There have been growing debates on the problematic effects of performance pressures. Often, public professionals are seen as ‘defenseless victims’ of systems and pressures – they are ‘professionals under pressure’. In this paper, we introduce a more positive way of understanding professionals and professional action in changing contexts. We see professionals such as teachers as ‘active agents’ who can develop and regain control over their own situation. Professionals can deliver quality, in spite of bureaucratic burdens and managerial intrusions. We call this ability professional capability: ‘the ability to proactively deal with work-related expectations, tasks and burdens in dynamic stakeholder environments’. This paper combines research on public administration, organizational sociology and occupational psychology, to generate a more productive understanding of proactive coping of professionals in public domains. We define and operationalize professional capacity, we explore sources and effects, and we develop hypotheses for further research.