Gomes Passos, nicknamed "Pele," signed a five-year contract with Inter.
A member of Portugal's under-21 team, Gomes Passos joined Guimaraes at the start of last season after a year with Benfica's reserve team. He appeared 10 times for Guimaraes last season in the second division and did not score any goals.
Also, Inter signed goalkeeper Enrico Alfonso from Chievo Verona.
Meanwhile, Inter has only three days remaining in this transfer period to figure out what to do with forward Adriano. Inter has indicated it would like to loan out Adriano but the player wants to either stay or leave on a full transfer.