The CityLab MobileLab is a forty-foot, fully equipped traveling laboratory that provides access to laboratory-based science experiences often unavailable to students and teachers. Since 1998, the MobileLab has served a variety of groups with a primary focus on middle and high school teachers and students. The MobileLab provides access not only to equipment rarely available to K-12 classrooms, but also to inquiry-based modules and expert educators that work with teachers to guide dynamic and effective science learning experiences. More than 60,000 students and teachers have been served by the MobileLab program. A significant benefit of the mobile laboratory concept is the equal opportunity it provides to diverse, often under-served, student populations. Boston University’s innovative CityLab program has been a leader in K12 science outreach since its inception in 1991. It has been instrumental in the development of mobile laboratory programs at institutions throughout the United States, Europe, and Hong Kong, and has been recognized as a model for science education by the Center for Excellence in Education.