After a brief introduction concerning bisalbuminemia, the authors go on to describe the specific cases they have observed: the subjects are all members of the same family. A total of 15 subjects have been observed; 8 of which have showed evidence of alloalbuminemia of the slow type. The parallel chemical and clinical investigations conducted have demonstrated no evidence of concomitant pathological situations. In addition, further checks carried out 20-30 days later have showed results identical to those of the first observation.