Line A – Senhor de Matosinhos – Estádio do Dragão Line A or the
Blue Line is the earliest of the five Porto Metro lines and the second busiest line as of 2023, transporting 12 million passengers. Between
Trindade and
Senhora da Hora stations, the line uses the inner part of the route of the
old Porto to Póvoa de Varzim railway line. Between Trindade and Estádio do Dragão stations it uses a new tunneled alignment, whilst between Senhora da Hora and Senhor de Matosinhos stations it mostly uses a new surface alignment, albeit with short sections coinciding with the route of the
Matosinhos branch railway.
Flexity Outlook Eurotrams number 001–072 service the line.
Line B/Bx – Póvoa de Varzim – Estádio do Dragão on Line B
Line B or the
Red Line runs between
Póvoa de Varzim and
Estádio do Dragão stations, has 34 intermediate stations and is the longest line of the system. Because of its length, the line provides two types of services: B and Bx. Although no extensions are planned, consideration was given to use the abandoned Famalicão branch of the old Póvoa Line, converted to a cycle path after closure, to reach Mourões and Barreiros, near
Avenida 25 de Abril.
Line C – ISMAI – Campanhã Line C or the
Green Line runs between
ISMAI and
Campanhã stations, with 22 intermediate stations. The line has a basic frequency of four trams per hour, but some trams on the line terminate at . Travel time between ISMAI and Campanhã stations is just over 40 minutes. The line reuses part of the route of the
old Porto to Guimarães railway line, albeit with a significant section of new alignment through the
city of Maia.
Line D – Vila d'Este – Hospital São João Line D or the
Yellow Line runs between
Vila d'Este and
Hospital São João stations, with 17 intermediate stations and a very visible crossing of the
River Douro on the upper level of the iconic
Dom Luís I bridge.
Line E – Aeroporto – Trindade (– Estádio do Dragão) Line E or the
Violet Line runs between
Aeroporto and
Trindade stations, with 13 intermediate stations. Trams run as far as Trindade every 15 minutes, with a journey time of around 30 minutes. Depending on day and time, between one and three trams an hour continue beyond Trindade to
Estádio do Dragão, serving a further four intermediate stations and taking about 10 more minutes. Line E was specifically built to serve
Porto Airport, and Aeroporto station is directly accessible from the terminal building. The station is at the end of a short branch off line B of the Metro, which it joins at , sharing tracks variously with lines A, B, C and F for the rest of its route. It is expected that the line will be extended from Senhora da Hora to Senhor de Matosinhos, which is the current teminus of Line A. This extension is shown on new official network maps of the Porto Metro, but as of February 2025 it has not been incorporated into the official timetable. Besides the shared segment between Senhora da Hora and Estádio do Dragão, Line F runs mainly above ground. It is the only service operating in the
municipality of Gondomar, and it transported 9 million people in 2024. ==Future expansion==