We report the finding of a female brown dog tick, Rhipicephalus sanguineus (Acari: Ixodidae) on the scalp of a male patient inPorto Alegre, Rio Grande do Sul, Brazil. Human parasitism by this tick is rare and has seldomly been reported in the literature, despite its recognized importance since it can act as a vector of Rickettsia rickettsii, the agent of spotted fever.