By train: Porrentruy station is on the Biel/Bienne–Delle line, with regular services to Biel (about 1 hour) and Delémont (30 minutes). From Basel, change at Delémont; the total journey takes around 1.5 hours. French TGV services reach Belfort (30 km away) from Paris in under 3 hours, from where local trains connect to Porrentruy.
By car: Porrentruy is on the A16 autoroute, the Transjurane motorway that links the Swiss Jura to Basel and France. From Basel it is about 50 km; from Bern, about 90 km.
From France: The town is close to the Alsace border and easily reached from Mulhouse (45 km) or Belfort (30 km). The border crossing at Boncourt is open continuously.