A case of cat-pork syndrome with subsequent follow-up in a 17-year-old male patient is reported. At the initial observation, the patient was sensitized to cat epithelium--along with house dust mites and grass pollen--from two years. In 2001 he had an immediate reaction with urticaria, angioedema and dyspnea after eating grilled meat and sausage, and skin tests and CAP/RAST revealed a sensitization to pork meat, with a value of 4.7 KU/L for pork meat, and of 55 KU/L for cat epithelium. The patient was followed up for three years with annual repetition of diagnostic tests. The elimination of pork meat from the diet was incomplete, with slight skin reactions to small amounts of cooked pork meat but tolerance to seasoned pork products such as salami. A challenge test with pork meat in 2004 was positive, with angioedema and asthma symptoms, and CAP/RAST showed a value of 43 KU/L for cat epithelium and 4 KU/L for pork meat. RAST inhibition confirmed the significant cross-reactivity between the two allergen sources. These findings provide some knowledge on the natural history of the cat-pork syndrome, and confirm that very prolonged avoidance of the offending foods are needed to expect a loss of sensitization.