Little is known about the main routes of human cytomegalovirus (HCMV) transmission in young adult populations. This study investigated risk factors for HCMV transmission in young adults attending university over a 3-year period. Blood samples were tested for HCMV specific viral capsid antigen IgG by enzyme immunoassay. Being born in a developing country and having lived in Africa were associated with HCMV seropositivity at study onset. No risk factors were associated with HCMV seroconversion over the 3-year follow-up. In contrast to previous reports, sexual activity was not associated with HCMV seroprevalence or seroconversion.