Communicability of rhinovirus type 16 or type 55 was studied in 24 childless couples; on partner (the donor) was infected with laboratory-grown virus. Initially, both partners lacked antibody to the challenge agent. Rates of transmission between partners were 41% and 33% for type 16 and type 55, respectively. These rates are similar to those determined in epidemiologic studies of natural rhinovirus infection. Although the mucosa of the anterior nares was shown to be highly susceptible to infection (less than one 50% tissue culture infective dose [TCID50]), transmission rarely occurred unless (1) at least 1,000 TCID50 of virus was recovered from the donor's nasal washing, (2) the donor had virus on his hands and anterior nares, (3) he was at least moderately symptomatic, and (4) he spent many hours with his spouse. Since person-to-person transfer of rhinovirus was so dependent upon time spent together and shedding of large amounts of virus by the donor, it seems possible that the chain of infection could be interrupted by environmental manipulation.