A retrospective analysis and prospective surveillance study were conducted to determine isolation rates of meticillin-resistant Staphylococcus aureus (MRSA) in dogs, cats and horses in Ireland. Clinical samples that had been submitted to University College Dublin (UCD) for routine microbiological examination over a four-year period (2003 to 2006) were analysed in the retrospective analysis, which included clinical samples from 3866 animals. In the prospective surveillance study, samples from healthy animals presenting for elective surgery as well as from animals with a clinical presentation suggestive of MRSA infection were investigated. Animals attending 30 veterinary practices throughout Ireland and a similar population of animals presented to UCD were studied. The isolation rates for animals in the retrospective study were 1.1 per cent (32 of 2864) for dogs, 0.7 per cent (four of 619) for cats and 5.2 per cent (20 of 383) for horses. The overall isolation rate of MRSA was 1.4 per cent (56 of 3866). Isolation rates for healthy animals in the prospective study were 0.4 per cent (one of 286) for dogs and 1.7 per cent (four of 236) for horses; MRSA was not isolated from cats (0 of 47). Isolation rates for animals suspected of being infected with MRSA were 8.1 per cent (14 of 173) for dogs and 4.6 per cent (three of 65) for horses; MRSA was not isolated from cats (0 of 47).