The present study was carried out with the aim of assess the occurrence of Cryptosporidium sp. infection in dogs and cats in Curitiba and its metropolitan area, state of Paraná, Brazil. Techniques employed to detect the protozoan in fecal samples were: staining by Ziehl-Neelsen for oocysts search and nested polymerase chain reaction (nPCR) targeting the 18SSU rDNA gene. To attempt the proposed aim, 91 feces samples of dogs and 25 of cats were collected and analyzed. Ziehl-Neelsen technique was unable to detect any oocyst in both groups analyzed, showing a very low sensitivity. Results of nPCR showed an infection rate of 13.2% (12/91) and 4% (1/25) in dogs and cats respectively. The implications of these epidemiological data are discussed in this work.