The Smithsonian Museum Conservation Institute Workshop on Biocolonization of Stone was the second workshop in a series and was dedicated to research on removal and control of biocolonization in stone objects. Twelve presentations were made, and the workshop ended with a roundtable discussion open to the 71 attendees. The goal was to provide a discussion forum for biologists, material scientists, and conservators interested in stone biodeterioration. Seven papers were presented, ranging from microbiological laboratory studies to combination of on-site testing and laboratory evaluation for World Heritage Sites such as Angkor Wat, to a literature overview. Five case studies were also presented, covering control of biodeterioration at Veterans Affairs cemeteries, experience gathered from the installation of zinc strips at the Stanford Mausoleum in San Francisco, the red staining found on the marble of the Memorial Amphitheater at Arlington National Cemetery, problems posed by deer stones in Mongolia, and the site test installed at San Ignacio Miní Jesuit Missions in Misiones, Argentina. The roundtable and discussions drew attention to the importance of exploring new methods to prevent microbial colonization of stone. Finally, in a closed session, suggestions were offered for developing criteria to evaluate microbial growth and determine when treatment is necessary. It was recommended that a database be prepared on stone biocolonization and its control.