Campylobacter species are a significant cause of sheep abortion in most sheep-raising countries. The relationship between the presence of Campylobacter spp. in fecal samples and reproductive disorders was investigated in 274 sheep from 28 properties in the state of São Paulo, Brazil. Biological samples from 16 aborted fetuses, one uterus, six placentas, five uterine secretion samples, five vaginal swabs, 17 semen samples, and three preputial swabs were also subjected to bacterial isolation. The bacteria were isolated from fecal samples of 14.9% (5/28) of the properties, affecting 3.65% (10/274) of the sheep, 3.5% (9/255) of females and 5.3% (1/19) of males. Campylobacter jejuni was the most prevalent species, present in 66.67% (7) of the positive samples, followed by Campylobacter coli, present in 22.22% (2), and one strain was identified as Campylobacter spp. The birth of "weak" lambs (p=0.06, OR=6.83 and CI=1.73 to 27.05) and neonatal death (p=0.087, OR=3.5 and CI=0.83 to 14.72) were associated with the fecal isolation of Campylobacter spp. Diarrhea was also associated with the bacteria (p=0.003, OR=9.83 and CI=2.19 to 44.18). The dissemination of Campylobacter spp. in Brazilian sheep is low and that, at present, the existing strains are not responsible for significant economic losses in sheep production, especially in adult animals. Campylobacter jejuni e Campylobacter coli estão presentes nos rebanhos paulistas e observou-se associação de ovinos com isolamento bacteriano fecal com quadro de nascimento de cordeiros "fracos" e consequente morte neonatal. Além de sua associação com quadros de diarreia que predispões à infecção oral de cordeiros a bactéria. A disseminação de Campylobacter spp. nos rebanhos ovinos Brasileiros é baixa e que, por enquanto, as cepas existentes não são responsáveis por grandes prejuízos na ovinocultura, principalmente em animais adultos.