Among the Greek manuscripts of Galen’s Commentary on the Hippocratic Aphorisms we find six exemplars now preserved in the Biblioteca Nazionale Marciana (BNM): Marc.gr. Z. 278, 277 and 285 and also Marc.gr. V 9, 5 and 10. Only the first one is an indispensable witness for the constitutio textus, but all seem to be fundamental for the reconstruction of the history of the tradition. This philological investigation provides information and palaeographical details about each of them - concerning handwriting, scribes, owners and genesis - retracing the philological relationships within the group and contributing to the historical sketch of the circulation of the Commentary in the Latin West, and particularly in Venice, during the Renaissance.