Ectoparasites are capable of transmitting infectious diseases and, therefore, are of zoonotic concern. Cats submitted to a spay/neuter program in the city of Rio de Janeiro were examined to determine the distribution of ectoparasites in cats from a city with a tropical climate. Independent of gender, breed, or age, 292 cats were combed and subjected to otoscopic examination. Ectoparasites were collected, and blood samples were taken to determine packed cell volume. The majority of the 292 cats were female (71%), and most of them were categorized as domestic short hair cats (92%). Different species of ectoparasites that produced both single agent and multi-agent infestations were detected in these cats. Most cats were infested by Ctenocephalides felis (60%); however, other ectoparasites were found to a lesser degree in the sampled population (Felicola subrostratus (5.4%), Rhipicephalus sanguineus (1.4%), Lynxacarus radovskyi (1%), and Otodectes cynotis (6.2%)). Within the infested cats, 16.3% were also anemic, and there was a significant association between the occurrence of anemia and flea infestation. Of all sampled cats, 65% were infested by at least one species of ectoparasites, which suggests both a heavy infestation of the environment and owner negligence. Ectoparasites are not only nuisances to both cats and owners, but they are also significant carriers of disease. Therefore, the implementation of rigorous, safe preventive measures is of great importance.