PurposeThe purpose of this paper is to discuss relationships between high-performance work systems (HPWSs) and productive/counterproductive behaviours initiated and performed by employees. Using the ability, motivation and opportunities (AMO) theoretical framework, the authors described how an HPWS influences employee behaviours. The authors suggest that HPWSs could increase productive work behaviour and decrease counterproductive behaviours by mediating employees' affective commitment and moderating their self-efficacy.Design/methodology/approachThis study is based on data from 563 questionnaires, which were completed using the computer-assisted telephone interview method. The respondents were knowledge workers, representing companies of various sizes in the Knowledge-Intensive Business Service (KIBS) sector in Poland. Statistical verification of the mediation and moderation analyses was conducted with macro PROCESS (ver. 3.3).FindingsThis research confirmed a significant statistical relationship between all examined variables. It has been shown that HPWSs influence productive and counterproductive behaviours both directly and indirectly through mediation of affective commitment. The statistical analysis also confirmed the study’s hypothesis that self-efficacy moderates relationships between an HPWS and employee behaviours.Research limitations/implicationsThis study has two limitations: its cross-sectional design and the use of self-reported questionnaire data.Originality/valueThis study is the first to explore mediating mechanisms between HPWSs and employee performance in the context of the KIBS companies in Poland. The results indicate that HPWSs are important antecedents of productive and counterproductive behaviours among knowledge workers.