Mycoplasma bovis infection was eradicated from a naturally infected dairy herd in Great Britain by a programme of identification, segregation and culling of infected animals. A series of group and whole milking herd tests was carried out over a period of 15 months, followed by a whole herd nasal swabbing. Cows were also sampled after calving and at drying off and bulk tanks were sampled at weekly intervals during the same period and for a further nine months. Fifty-nine cows were identified as excretors, the majority in group or herd tests, but five after calving and three at drying off. Eight of the original clinical cases were retained in the herd, after repeated negative test results. Bulk tank sampling was found to be extremely useful in detecting infection even down to one cow in a milking herd of 300. The value of milking hygiene and the indications for eradication are also discussed.