The results of an experimental infection of sheep with a field strain of Mycoplasma agalactiae are reported. Six sheep, seronegative to M. agalactiae were used: three sheep were inoculated by the conjunctival route (group A) and three sheep intranasally (group B). The clinical signs were observed 20 days after infection but the shedding of Mycoplasma agalactiae, particularly from the nasal route and with milk, started a few days post infection (d.p.i.) (1st d.p.i. and 9th d.p.i. respectively). Antibody titers were first detected after 28 d.p.i. in group B and after 35 d.p.i. in group A.