Medical writers, document quality reviewers, and document specialists work together to produce high-quality clinical and regulatory documents. Cross-functional collaboration with other functional leads like bio statisticians, medical monitors, and project leaders is also crucial for timely project delivery. We interviewed people in these roles who emphasised that clear communication, setting clear expectations, addressing challenges proactively, and leveraging digital tools are all needed for successful cross-functional and cross-regional collaboration. Understanding different perspectives and roles, practicing active listening, and being mindful of time zones and cultural differences are also important when working in multidisciplinary and global teams. Overall, effective collaboration leads to better outcomes and competitive advantage in medical writing. Medical Writing. 2024;33(4):12–18. https://doi.org/10.56012/lakw6114