PurposeThe current study aimed to investigate how perceived human capital sustainability leadership (HCSL) affects work outcomes (i.e. work engagement and job satisfaction), specifically through the mediating role of knowledge sharing behaviour in the hospitality industry. Building on social exchange theory and conservation of resources theory, the authors propose that knowledge sharing behaviour is an attempt to share and expand an individual's resources, which in return motivates employees during work. Furthermore, through the mediating effect of knowledge sharing behaviour, the authors attempt to provide empirical evidence for organisational actions and employees’ reciprocating actions, therefore, triggering positive contribution.Design/methodology/approachThe authors methodologically employed structure equation modelling for the analysis which includes reflective–formative higher-order construct (HOC) (i.e. HCSL). The authors tested the hypotheses with partial least square structure equation modelling (PLS-SEM) from a sample of 382 hotel employees who were selected through purposive sampling.FindingsThis study’s findings suggest that the employee engagement and job satisfaction regresses on HCSL and knowledge sharing behaviour. The study’s analysis also suggests that the relationships between the HCSL and work outcomes are mediated by knowledge sharing behaviour.Originality/valueThis study contributes to the sustainability leadership literature by looking into the integrated model of sustainable leadership from its four dimensions (i.e. sustainability leadership, ethical leadership, mindful leadership and servant leadership) and its consequences for work outcomes. Furthermore, the authors examined how knowledge sharing behaviour, being an underlining mechanism, affects these relationships, thus having implications for academia and practitioners.