The Metro was built to relieve the traffic congestion between the city and San Miguelito District and to offer commuters a viable alternative to road transport, as the MiBus transit system was suffering multiple issues.

After an exhaustive inspection of all proposals for the construction of the railway system, the Línea Uno consortium, which includes the Spanish Fomento de Construcciones y Contratas (FCC), won the contract.

The third and the fourth phases of the project took place between 2011 and 2012 and consisted of the construction of all viaducts and stations and the relocation of the public utilities.

The control center that supervises the whole metro operations and the Automatic Train Supervision was provided by Thales, along with the network infrastructure and communication and security solutions including CCTV, telephony, intercom, TETRA radio, visual and audio information to passengers, and fire detection.

By September 2013, construction of Line 1 was 92% complete, which allowed a test run with some of the rolling stock.

The authority in charge of the planning, construction, and execution of the project had a budget of $200 million for the year 2012.

[citation needed] In December 2011, the Secretaría del Metro de Panamá clarified that the updated cost of the project is US$1.880 billion, including public utilities relocations and engineering and project management costs.

[3] On May 16, 2014, three different consortiums offered several proposals for the planning, cost estimation, and technical feasibility of Line 2 of the system.

[23] After making a detailed inquiry of all proposals, the Metro de Panama secretary announced on July 12, 2014, that the PML2 consortium, which includes the Spanish "Ayesa Ingeniería y Arquitectura", the "Barcelona Metro", and the American "Louis Berger Group," had been awarded the contract.

[28] Originally, Line 2 had to be delivered in April 2019, but since Panama City was hosting the Catholic World Youth Summit in January 2019, construction was being accelerated, and a new delivery date was announced as December 31, 2018, to serve the one million tourists who were expected to attend the summit.

[29] However, in 2018, a month-long labor strike eroded over US$900 million from the annual GDP figure and caused the same amount of losses.

However, the first test ran with 12 trains for 8 hours was conducted on December 28, with a partial opening on January 15 with five stations for the summit.

[30] In August 2018, it was announced that Line 2 would operate partially from Corredor Sur to San Miguelito 24 hours a day during the summit.

[28] On March 16, 2023, a branch of Line 2, known as El Ramal, connecting Corredor Sur and Tocumen International Airport, Aeropuerto, was opened.

The stations are: San Miguelito, Paraíso, Cincuentenario, Villa Lucre, El Crisol, Brisas del Golf, Cerro Viento (this station gives access to Metromall and Centro Comercial Los Pueblos), San Antonio, Pedregal, Don Bosco, Corredor Sur (station of interchange with "El Ramal"), Las Mañanitas, Hospital del Este, Altos de Tocumen, 24 de Diciembre and Nuevo Tocumen (where the maintenance shop of Line 2 is located).

[39] An extension of the line one stop to the north to a new station at Villa Zaita was completed and began operation in April 2024.

[42] Line 2 will run for 29 km (18 mi) from Parque Urraca, in the Punta Pacifica district to Felipillo, and will be built in three phases.

[39] Phase 1 is 21 km (13 mi) long, and as of September 2018, the new line was 85% complete, allowing for test runs until Cerro Viento station with four (5-car) trains.

Fourteen trains were operational in the World Youth Day in January 2019 in manual mode at a top speed of 40 km/h (25 mph).

A branch line is proposed that would start on Condado del Rey station and run along the Via Centenario until it reaches MERCA Panama.

[51] There are plans for a second phase two extending the line to La Chorrera, with the Japanese government approving a US$697 million loan for project development.