Mycoplasma suis, the etiological agent of swine hemoplasmosis, has been neglected in swine herds around the world. Swine hemoplasmosis is frequently associated with hemolytic anemia, disgalacty, infertility and immunosuppression, and it results in significant economic losses. This study investigates the occurrence of M. suis in non-technified swine herds in the northeastern region of Brazil using quantitative PCR (qPCR) based on the 16S rRNA gene. Between March and August 2013, blood samples from 147 swine were collected during slaughter in the city of Mossoró, state of Rio Grande do Norte, northeastern Brazil. One hundred and twelve samples (76.19%) were positive for M. suis by qPCR assays. The range of Cqs and quantification (copies of a M. suis-16S rRNA gene fragment/µL) was 20.86-37.89 and 1.64×101-6.64×107, respectively. One can conclude that M. suis infection have high occurrence (76,19%) in non-technified swine-rearing systems in Mossoró in the state of Rio Grande do Norte, Brazil.