In December, 1999 an elevated two-line 'Skytrain' (officially called BTS) metro system was opened.

The BTS Skytrain is the safest, most comfortable and convenient way to get around Bangkok. Each train can carry over 1,000 passengers, making the BTS Skytrain the most environmentally friendly mass transit system in Thailand.

Currently there are 23 stations and two routes, the Sukhumvit Line and the Silom Line. The Sukhumvit line runs northwards and eastwards, starting from Mo Chit, Saphan Khwai, Ari, Sanam Pao, Victory Monument, Phaya Thai, Ratchathewi, Siam, Chit Lom, Phloen Chit, Nana, Asok, Phrom Phong, Thong Lo, Ekkamai, Phra Khanong and terminating at On Nut. The Silom line plies Silom and Sathon, the Central Business District of Bangkok, starting from National Stadium, Siam, Ratchadamri, Sala Daeng, Chong Nonsi, Surasak and terminating at Saphan Taksin. The lines interchange at Siam station and have a combined route distance of 23 km. They cover much of the central city and its many commercial, residential and tourist areas, with extensions planned to outlying areas.

The trains run daily between 6:00 am and 12:00 midnight.