As part of annual colony counts in Santa Cruz Province, Argentina, a health survey of rockhopper penguins (Eudyptes chrysocomes) was conducted in 1994. Forty-five birds were examined during handling procedures, and blood and fecal samples were collected for laboratory analysis. All birds appeared to be in good condition. No ecto- or endoparasites were found. Hematology, plasma chemistry, and plasma mineral levels were measured and correlated with the results of bacterial and viral serology. Antibodies against Chlamydia sp., avian adenovirus, avian encephalomyelitis virus, infectious bronchitis virus, avian reovirus, and paramyxovirus-1, -2, and -3 were found. Mean plasma chemistry and mineral values differed between individuals testing positive and negative on serologic tests. There was no serologic evidence of exposure to avian influenza virus, duck viral enteritis, infectious bursal disease, infectious laryngotracheitis, Aspergillus sp., or Salmonella pullorum. Trace amounts of endrin were found in the plasma of one bird, but all other chlorinated pesticide and polychlorinated biphenyl levels were below detectable limits.