Background: An outbreak of Hantavirus Cardiopulmonary Syndrome (HVCS) caused by the Andes virus, affected Chile since 1995. Antibodies to Hantavirus in health care workers who had cared patients with HVCS in Coyhaique, Argentinean reports and familial clustering of hantaviral illness, raised the possibility of person to person transmission. Familial clustering could occur secondary to a similar exposure to a common infected environment of more than one member of the family. Moreover, the prevalence of antibodies in health care workers in Coyhaique does not differ from the prevalence in general population in that region. Aim: To study the prevalence of antibodies to Hantavirus in health care workers exposed to body fluids of 20 patients. Material and methods: Among health care workers exposed to patients with HVCS, we registered information about the exposure to patients and to the environment outside the hospital in which they could have been infected. IgG antibodies against Hantavirus were measured by ELISA using two dilutions. Results: Sixty seven workers were studied. Of these, 73% were exposed.to respiratory secretions and blood, 21% to blood and 6% to respiratory secretions. Only 6% protected themselves properly, 49% used facial masks and gloves, 25% only facial masks, 7% only gloves and 12% used no protection measures. In none of these workers, Hantavirus antibodies were detected. Conclusions: These results are supporting evidence against person to person transmission of the Andes virus. (Rev Méd Chile 2000; 128: 735-9).