The protozoan parasite Neospora caninum is a major cause of abortion in cattle worldwide. The aim of the present study was to determine and to compare the presence of anti-Neospora caninum antibodies in cattle, as well as in farm dogs, and the relationship among them. The research was conducted in different mesoregions of Paraná state, Southern Brazil. Sera from 1.263 cattle, from 77 farms were tested for antibodies to N. caninum by ELISA. Sera from 129 dogs, from 35 farms were tested for antibodies to N. caninum by indirect fluorescent antibody test (IFAT). Antibodies to N. caninum were found in 423 of 1.263 bovines (33%), and in 32 of 129 dogs (25%). The seroprevalence of antibodies for N.caninum in cattle was not significantly higher in farms with seropositive dogs when compared to farms with no seropositive dogs. Thus, these results suggest that seropositive dogs to N. caninum did not contribute for the seroprevalence in cattle. Neospora caninum is widespread among cattle and dogs from rural areas of all mesoregions of Paraná, Brazil.