[3] It runs in the northern part of the Bangkok Metropolitan Area from Nonthaburi Civic Center in Pak Kret district, Nonthaburi along the major east–west transport corridor of Highway 304 (Chaeng Wattana and Ram Inthra roads) to terminate at Min Buri in Min Buri district in east Bangkok.

It opened for free public trial operation on 21 November 2023[4] with Prime Minister Srettha Thavisin taking the inaugural ride.

On 9 December 2021, daily testing conducted at a maximum speed of 25 km/h (16 mph) began on a short 4 km (2.5 mi) section of the line between the depot at Min Buri and Bang Chan station.

[8] In April 2022, the acting Director-General of the Department of Rail Transport stated that the line would not begin full testing until September 2022 and that the first stage would not open until late December 2022.

[9] In May 2023, a further 345-day extension was announced by the MRTA, delaying the start of trial operations for the initial section and later the final opening of the full line to June 2024.

[11] The line opened for free public trial operation on 21 November 2023 and officially launched on 18 December 2023.

It interchanges with the SRT Dark Red Line at Lak Si Station and passes over Vibhavadi Rangsit Road running east through the Ram Intra intersection and the Lak Si monument in Bang Khen District, where it crosses under the BTS Sukhumvit Line and interchanges with Wat Phra Sri Mahathat.

The director-general of the Office of Transport and Traffic Policy and Planning had previously stated in an interview that the Pink Line was considered a priority scheme to be completed by 2017–18, as it ran past the then recently opened Bangkok Government Complex.

[14] A review was undertaken in early 2012 to reconsider the heavy rail option, but cost restraints prevailed and the Office decided to continue with the monorail plan.

In October 2012, members of the new government requested to extend the planned line east by 3.4 km (2.1 mi) beyond the Min Buri terminus to Nong Chok.

[18] A coup in May 2014 resulted in a new military administration and the tender being deferred while a review of all mass transit projects was undertaken for a period of 18 months.

On 16 June 2017, contracts were signed by the BSR consortium with the Mass Rapid Transit Authority of Thailand.

[20] The BSR established the Northern Bangkok Monorail Company Limited (NBM) to operate the line.

Construction of the Pink Line began in December 2017 with the BSR consortium establishing a number of preparation work sites and closing lanes along the east-west Chaeng Wattana-Ram Inthra corridor.

[22] Construction work on Tiwanon Road began at the end of October 2018 with the temporary closure of long stretches of the middle lanes between Khae Rai and Pak Kret intersections.

A new EIA was completed for the relocation, but the new station location required Cabinet approval, causing delays to the opening of this section of the line.

[34] On 9 December 2021, daily testing conducted at a maximum speed of 25 km/h (16 mph) began on a short 4 km (2.5 mi) section of the line from the depot at Minburi to Bang Chan station.

[42] On 9 February 2021, Cabinet approved the 2.8 km (1.7 mi) spur line which is expected to cost 3.37 billion baht.

Finally, on 20 June 2022 the MRTA issued a Notice to Proceed for the now 4.2 billion baht spur line and soon after construction commenced.

[36] The MRTA may also consider a further 2 km (1.2 mi) extension in the future from Muang Thong Thani to Tiwanon road.

The first set was shipped on 4 September 2020[48] and arrived in Thailand on 1 October at Laem Chabang port with a handover ceremony attended by the Thai Prime Minister, the Bangkok Mass Transit System PLC.

This measure aims to address the worsening air pollution caused by surging dust levels across all districts of the capital.