PurposeBased on conservation of resources theory and incivility spiral theory, this study examines the relationship between supervisor incivility and turnover intentions by investigating the mediating roles of co-worker incivility and emotional exhaustion.Design/methodology/approachA serial mediation model was empirically tested with a sample of 600 employees in Greek small and medium-sized enterprises (SMEs).FindingsResults indicate that supervisor incivility is linked to turnover intentions in three main ways. Directly, indirectly through emotional exhaustion, and indirectly through the serial mediation of co-worker incivility and emotional exhaustion.Research limitations/implicationsPossible limitations of the study include the sampling techniques and the self-reporting measures for data collection.Practical implicationsFindings attest that owners and managers of SMEs should take note of the trickle-down effect, namely that their own misbehavior will fuel co-worker incivility. Supervisor incivility has cumulative, deleterious consequences on employees, depleting their emotional resources and enhancing turnover intentions, and should therefore be restricted through appropriate practices.Originality/valueFew empirical studies have explored the effects of supervisor incivility on the incivility manifested by others and their impact on turnover intentions. The study enriches the trickle-down effect literature by identifying an additional indirect path linking supervisor incivility and turnover intentions. Further, this study took place in SMEs, a context with limited research in abusive supervision and incivility yet highly pertinent, given that SMEs informality might leave such behavior unchecked.