The Gordon Research Conference on Cilia, Mucus, and Mucociliary Interactions, held from February 27 to March 4, 2005, at the Rancho Santa Barbara Marriott in Buellton, California, will provide a unique opportunity for scientists involved in ciliary, mucous and mucociliary research to present their latest progress and to exchange ideas, thus bringing together a very diverse group of scientists who usually do not meet. Abnormal cilia and mucus contribute to a variety of human diseases including diseases of the airways, abnormal left-right asymmetry, and polycystic kidney disease to name a few. Many of these diseases have no effective or only limited treatment options. Thus, there is a clear need for a small meeting focusing on these topics. As a Gordon Research Conference, the meeting will follow the highly successful model of such conference layouts and will offer 9 plenary sessions and additional poster sessions. Three of the plenary sessions will be devoted to cilia, one to primary ciliary dyskinesia, three to mucus and mucins, and two to mucociliary interactions. The organizing committee has invited an international and diverse group of many young but also established investigators to present their work during plenary sessions. Discussions have been recognized to be vital to the success of the conference and ample time for these will be allowed between speakers during plenary sessions, facilitated by discussion leaders. Finally, poster sessions will complement the plenary sessions and free afternoons will further enable idea exchanges between scientists.