A workshop/symposium on “Mucociliary and Cough Clearance (MCC/CC) as a Biomarker for Therapeutic Development” was held on October 21–22, 2008, in Research Triangle Park, NC, to discuss the methods for measurement of MCC/CC and how they may be optimized for assessing new therapies designed to improve clearance of airway secretions from the lungs. The utility of MCC/CC as a biomarker for disease progression and therapeutic intervention is gaining increased recognition as a valuable tool in the clinical research community. A number of investigators currently active in using MCC/CC for diagnostic or therapeutic evaluation presented details of their methodologies. Attendees participating in the workshop discussions included those interested in the physiology of MCC/CC, some of who use in vitro or animal methods for its study, pharmaceutical companies developing muco-active therapies, and many who were interested in establishing the methods in their own clinical laboratory. This review article summarizes the presentations for the in vivo human MCC/CC methods and the discussions both at and subsequent to the workshop between the authors to move forward on a number of questions raised at the workshop.