Five dogs were presumptively diagnosed with immune-mediated thrombocytopenia. As they had all been chronically treated with non-steroidal anti-inflammatory drugs, administration of immunosuppressive doses of corticosteroids was considered contraindicated. Non-steroidal anti-inflammatory drugs were temporarily discontinued in all the dogs and mycophenolate mofetil was introduced as first-line single immunomodulatory therapy. This treatment protocol resulted in complete remission of immune-mediated thrombocytopenia in all the dogs, and mycophenolate mofetil was discontinued after several months of therapy in four of the five dogs with no relapses, even when non-steroidal anti-inflammatory drug administration was resumed. The remaining dog required continued mycophenolate mofetil therapy to avoid relapse. One dog experienced diarrhoea, and another dog had diarrhoea and decreased appetite.