You should read the guide: How To Get Laid in Bangkok.
Prostitution is illegal in Thailand, although in practice it is tolerated and partly regulated.
More than 10,000 girls are reckoned to be working the trade in Bangkok, and large numbers of them are easy to pick up in bars in some tourist areas. Average metrics of Thai girl 155cm, 49kg and dark hair.
Bangkok is a big city and there are huge amount of ladies for men.
Visiting any one of the areas below you will discover a carefree party atmosphere where you can dance, sing (karaoke), drink, eat and meet girls as if you were in your hometown disco.