Due to improper infrastructure planning and the inadequate size of the rolling stock (to transport a large number of passengers in or out of the downtown Kuala Lumpur area during rush hour), the KL Monorail is commonly cited as the most unsatisfactory rail line of the Klang Valley Integrated Transit System.

[4][5] This urban monorail line was opened on 31 August 2003, with 11 stations running 8.6 km (5.3 mi) on two parallel elevated tracks.

The 14 km (8.7 mi), 22-station system is designed to carry more than 34,000 passengers a day on a 20-minute loop through Kuala Lumpur's bustling commercial core.

[7] According to plans dating back to the 1990s, the planned line was to have two branches (similar to the Ampang and Sri Petaling Lines), with one branch going via Maharajalela station and then on to the city centre, and the other branch going to Mid Valley, Abdullah Hukum, Jalan Klang Lama and ending at Kampung Pasir, which will probably include integration with KTM Komuter's Port Klang Line at Petaling or Pantai Dalam stations.

While another plan from Kuala Lumpur People-Mover Rapid Transit (PRT), under the "Kuala Lumpur Linear City" development plan, depicts that the project will include building 16 kilometres (9.9 mi) of twin track monorail guideway beams, 20 elevated stations, two depots and 14 monorail trains.

The main contractor is a local company, BNK, which had little success in its search for backers to finance its share of the venture.

[7] Construction was re-initiated by Hitachi, Ltd., but the 1997 Asian financial crisis led to cessation of work in December 1997.

Based on 1999 transit map, Originally KL monorail line have 19 stations, start from Titiwangsa, Chow Kit, Wawasan, P. Ramlee, Raja Chulan, Bukit Bintang, Imbi, Hang Tuah, Merdeka, Sultan Sulaiman (cancelled), Tun Sambanthan, subsequently unbuild line from Syed Putra, Taman Seputeh, Abdullah Hukum, Lembah Pantai, Pantai Dalam, Taman Desa, OUG and Kampung Pasir.

[13] Since the start of operations, the KL Infrastructure Group suffered losses due largely to depreciation and interest repayment costs.

[citation needed]A due diligence audit was conducted from 5 March 2007 to 27 April 2007 by consultants appointed by the government.

Following agreement to the takeover, BPM granted KL Monorail an extension until 29 April 2007 for an interest repayment amounting to MYR 4,244,801.91, which was originally due on 29 December 2006.

[17] However, the takeover seemed to have suffered a setback at least from the perspective of KL Infra when on 26 March 2007, it was notified by BPM that it was not going to entertain any further extensions for interest repayment.

[citation needed]On 14 May 2007, Mohd Anwar Bin Yahya and Cho Choo Meng were appointed receivers and managers by Amanah Raya, the Security Trustee for BPM.

[20] On the same day, KL Infra's board announced to Bursa Malaysia that it had formed the opinion that it was not solvent and would not be able to pay all its debts in full within a period not exceeding twelve months.

Pedestrian access to  KJ10  KLCC on the LRT Kelana Jaya Line via an elevated walkway from Pavilion Kuala Lumpur.

Connecting station, without paid-area integration, to  KJ12  Dang Wangi on the LRT Kelana Jaya Line.

The project also includes the installation of a new signalling system, construction of a new depot to accommodate larger train sets, and other station upgrades and universal access facilities.

Touted as one of the busiest stations of the line due to its proximity to Bukit Bintang, [citation needed] the hub of shopping and entertainment in Kuala Lumpur, it used to have only one exit, but the upgrading project now provided the station with added an alternative entrance and exit walkway and a direct entry to the Lot 10 and Sungei Wang Plaza shopping complexes.

The completion of the overhead bridge now enables customers to travel between KL Sentral and the monorail station safely and conveniently.

[29] These were also manufactured by Scomi, this time to the company's in-house-developed SUTRA design, which was also ordered by the Mumbai Monorail line in India.

[29] The first two sets four-car trains entered service in December 2014, with the remaining units scheduled to be arriving in stages.

Prior to the opening, on 16 August 2002 an accident occurred during a test run involving a 13.4 kg (30 lb) safety wheel falling off a train and hitting the head of a pedestrian walking under the monorail viaduct at Jalan Sultan Ismail.

On 7 March 2003, Chelliah filed a MYR 5 million negligence suit against the companies involved in the design, installation and operation of the trains, as well as the Director-General of Railways.

[34][35] On 8 April 2003, the High Court ruled that the Monorail company was liable for the incident, but not the Director-General of Railways.

Although the monorail company reported that any such accident was "unlikely" as six bolts would have to be removed for it to occur and furthermore, a check of all 23 other safety wheels on the train involved did not turn up any other issues, the high court judgement ruled that the monorail company "failed to provide a reasonable explanation as to how the safety wheel had come off the train and instead relied on the possibility that there had been tampering by unknown persons".

[40] On 30 March 2015, a monorail service was temporarily delayed when a tyre of a two-car train coach caught fire at the Titiwangsa Station.

[43] On 7 May 2024, a 50-year old tree near Concorde Hotel Kuala Lumpur collapsed on Jalan Sultan Ismail, hitting 17 vehicles and the nearby monorail tracks, causing one death and 1 injured.