Since Business Process Management (BPM) and sustainability often evolve along separate journeys, few organizations fully recognize the potential of integrating both disciplines to address shared tensions and to optimize sustainability-driven business process transformation. Hence, this study investigates the convergence of BPM and sustainability journeys through multiple case studies, applying paradox theory and BPM capability frameworks to analyze emerging tensions and response strategies. The findings reveal that despite their different starting points, both BPM and sustainability journeys face shared paradoxical tensions. Our research also contextualizes existing BPM capability areas for identifying shared solutions to navigate the tensions. This study offers theoretical contributions by extending BPM capability frameworks to address sustainability paradoxes and by introducing process-level capability considerations to sustainability research. Our research provides practical insight into fostering collaboration between BPM and sustainability functions that enable organizations to more effectively navigate the complexities of managing sustainable processes.