The authors agree that the surname derives from the name of the trade of physician and that its fixing as a surname is documented from the 12th century. E. De Felice notes that as early as 1156 the Latinized form Medicus appears in Genoa. E. Rossoni supplies a deed of sale dated 1175 in Pavia, in which a certain Otto, son of Guidone Medici, is mentioned, as an early testimony of this process.

As for the geographical distribution, De Felice indicates that the surname is sporadic in Italy generally, with a high frequency in Liguria and Emilia-Romagna. Rossoni specifies that it is found throughout Italy, with the greatest presence in Lombardy and Emilia-Romagna. As for the variant Medico, De Felice considers it rare and limited to the south-east of the country, while Rossoni identifies a core between the provinces of Bari and Brindisi, and another at San Cataldo, in the province of Caltanissetta.

Rossoni also recalls the celebrated De' Medici family of Florence, whose most illustrious member was Lorenzo the Magnificent (1449–1492).