There are two options for travelling between Porto and Salamanca by public transport as follows:
Rail:
There is a daily train connection between Porto and Salamanca as follows:
Porto-Campanha Dept: 22h00
Salamance Arr: 04h53 (Spanish Time)
Transit Time: +- 6hrs.
Change trains at Coimbra B
See: www.cp.pt
Bus:
There is currently a Monday to Saturday service operated by intercentro.pt / alsa.es as follows:
Porto Dept: 10:15
Salamanca Arr: 17:30 (Spanish Time)
Transit time: 6hrs15min
On Sundays the service runs as follows:
Porto Dept: 20:30
Salamanca Arr: 03:00 (Spanish Time)
Transit time: 7hrs30min
The bus departs from the InterCentro/InterNorte Bus Station at Metro Casa da Musica in the Boavista area of Porto.