The Tourism and Sports Ministry wants to push sports tourism to another level by promoting "Amazing Thailand Marathon Bangkok" as a major race in Asia within three years.
The event is part of a series of five Amazing Thailand marathons the Tourism Authority Thailand (TAT) will hold throughout 2020.
Phiphat Ratchakitprakarn, the tourism and sports minister, said the annual marathon is scheduled on the first Sunday of February, falling on Feb 2 next year.
Some 30,000 participants are expected to join, of which more than 5,000 will be foreigners, helping to generate tourism receipts in the first quarter of at least 900 million baht, Mr Phiphat said.
He said runners can enjoy Bangkok's iconic landmarks such as Ratchadamnoen Avenue, Wat Saket and Democracy Monument.
The Bangkok Marathon aims to be certified by the International Association of Athletics Federations with a bronze label by the end of this year to guarantee the standard of the competition.
The marathon series will be in its third edition next year, receiving support from the Sports Authority of Thailand, the Public Health Ministry, Bangkok Metropolitan Administration and Thailand Tri-league.
TAT governor Yuthasak Supasorn said last year's event was affected by dust pollution, with PM2.5 levels labelled as unhealthy in the capital, forcing 20% of participants to cancel.
Mr Yuthasak said the TAT will monitor the air quality closely and do a better job of cleaning the streets and restricting road construction near the course to protect runners' health.
During the event, air quality sensors will be installed at every 2-3 kilometres, while more water stations will be supplied. Runners can check their respiration with the Public Health Ministry after the race.
Most foreign runners last year were from China, followed by Australia, Singapore, Hong Kong and Malaysia.
TAT will also seek approval from the cabinet to organise marathon events in Buri Ram, Chon Buri, Phuket and Ratchaburi.
