This article aims to investigate the impact of toxic leadership (TL) on counterproductive work behavior (CWB) with the mediating roles of organizational cynicism (OC) and organizational injustice (OIJ), using 392 questionnaires collected from employees working in the Egyptian higher education sector. The data are examined using AMOS 25 for structural equation model (SEM) analysis. The results show that toxic leadership positively affects CWBs, organizational cynicism, and organizational injustice. Furthermore, organizational cynicism positively affects CWBs, and organizational injustice significantly affects CWBs. Finally, organizational cynicism and injustice partially mediate the relationship between toxic leadership and CWBs. This study adds novelty to the literature by exploring the influence of toxic leadership on CWBs, OC, and OIJ in Egypt’s higher education sector. As a result, addressing the prevalence of toxic leadership and its ripple effects is essential for fostering sustainable organizational cultures. Sustainable work environments prioritize fairness, employee well-being, and positive leadership practices, reducing counterproductive behaviors. Finally, this article reviews the limitations but also assesses the substantial contributions to theory and practice made by the paper.