Natural and experimental infections have shown that cats are susceptible to highly pathogenic avian influenza A virus subtype H5N1 (HPAIV H5N1). Cats can be severely affected and die from the disease, but subclinical infections have also been reported. To learn more about the role of cats in the spread of the virus and about the risk posed to cats, the prevalence of H5N1 virus was examined in 171 cats from areas in Germany and Austria in which birds infected with HPAIV H5N1 had been found. Pharyngeal swabs were examined for H5N1 virus using real-time polymerase chain reaction, and serum samples were tested for antibodies to influenza virus. None of the cats showed evidence of infection with H5N1 virus. Prevalence of H5N1 virus was determined to be <1.8% (95% confidence interval (CI): 0.000000-0.017366); prevalence of antibodies was <2.6% (95% CI: 0.000000-0.025068).