We analyse two cases of Bovine Serum Albumin (BSA) allergy. The first regards a female laboratory technician with a history of bronchial asthma due to cat allergy, who developed an exacerbation of bronchial symptoms as a consequence of BSA powder inhalation at work. To date, sensitization to BSA as a cause of occupational asthma has rarely been reported in the scientific literature. The second case concerns a woman with a similar cat sensitivity, who presented an oral allergy syndrome-type clinical reaction, gastric pain and diarrhoea immediately after eating cooked pork meat. Subsequently, she developed the same reaction after eating goat meat and goat cheese, and then also after eating beef. Both patients resulted specifically sensitized to BSA and to other mammalian serum albumins which play a role as panallergens in animals. The two cases show that BSA, a well known cause of food allergy in childhood, may also provoke symptoms of food allergy in adulthood, though in case of powder inhalation, it may provoke respiratory symptoms. Prior animal sensitization appears to represent a risk factor.