From May 15, 2005 to April 15, 2008, 1878 cases of neoplasms in dogs were reported to the web‐based Danish Veterinary Cancer Registry. The proportions of malignant (38 per cent) and benign (45 per cent) tumours were similar. The most common malignant neoplasms were adenocarcinomas (21 per cent), mast cell tumours (19 per cent) and lymphomas (17 per cent). The benign neoplasms most commonly encountered were lipomas (24 per cent), adenomas (22 per cent) and histiocytomas (14 per cent). Skin (43 per cent) and the female reproductive system including mammary tissue (28 per cent) were the most common locations of neoplasia. There was a distinct breed predisposition for tumour development, with a high standard morbidity ratio (indicating a higher risk of cancer) for boxers and Bernese mountain dogs. A standard morbidity ratio below 1 was observed in German shepherd dogs and Danish/Swedish farm dogs, suggesting a lower risk of cancer in these breeds.