Drawing on the attraction-selection-attrition (ASA) framework, this paper examines a mechanism, namely person-organization (P-O) fit, through which high performance HR practices (HPHRP) affect two negative employee outcomes: work-related stress and quit intentions. Using a sample of Egyptian public health sector workers, a mediation model is tested empirically using structural equation modelling. The study results show that HPHRP positively affected P-O fit, which in turn had significant negative associations with work stress and quit intentions. P-O fit also explained a high proportion of mediation in the relationship between HPHRP and both outcomes.