Last updated on October 27, 2025
No, while not wearing underwear is not explicitly illegal in Thailand, appearing in public in a way that causes visible indecency or public discomfort may violate Section 388 of the Thai Penal Code, which prohibits acts offensive to public order or morals.
What Lies Beneath the Law
Thailand’s streets are a kaleidoscope of color, culture, and contrast. From the serene calm of Buddhist temples to the electric buzz of Bangkok’s nightlife, the country embraces diversity—but with boundaries. When it comes to what you wear (or don’t wear) under your clothes, the law doesn’t peek. But if your choice leads to public exposure or discomfort, the law may step in.
There’s no statute in Thailand that directly mandates the wearing of underwear. However, the Thai Penal Code, particularly Section 388, sets the tone for public behavior. It states that anyone who causes a nuisance or behaves in a way that offends public morality in public spaces can be fined. The law doesn’t care about your undergarments—it cares about the impact of your appearance on others.
Culture of Courtesy
Thailand’s social fabric is woven with values of modesty and mutual respect. The concept of “rak sa nam jai”—preserving harmony and avoiding embarrassment—is deeply ingrained. Dressing appropriately is seen as a sign of respect, not just for tradition but for those around you.
In temples, government offices, and even some malls, dress codes are enforced. Revealing clothing is discouraged, and visitors are often asked to cover shoulders and knees. While these rules don’t extend to underwear, they reflect a broader expectation: don’t make others uncomfortable.
Legal Boundaries and Public Spaces
Let’s say someone skips underwear for comfort. If their outerwear is opaque and covers them adequately, they’re unlikely to attract legal attention. But if the choice results in visible exposure—through sheer fabrics, wardrobe malfunctions, or intentional display—it could be interpreted as indecent.
Section 388 of the Thai Penal Code allows for fines up to 1,000 THB (about USD 27) for acts deemed offensive to public order. This includes indecent exposure, loud disturbances, or any behavior that causes discomfort in public settings. Enforcement is discretionary and context-dependent, often influenced by location, time, and social setting.
Discretion and Enforcement
Thai police and municipal officers have broad discretion in interpreting what constitutes public indecency. In tourist-heavy areas like Pattaya or Phuket, enforcement may be more relaxed, but that doesn’t mean it’s a free pass. In more conservative regions or during cultural events, expectations are stricter.
The Ministry of Justice and the Royal Thai Police emphasize maintaining public order and cultural harmony. While there’s no “underwear law,” behavior that draws negative attention or disrupts public peace can be penalized under general nuisance laws.
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Sources
Thai Penal Code Section 388 – Office of the Attorney General
https://www3.ago.go.th/center/wp-content/uploads/2022/06/Criminal-Code-1956.pdf
Ongoing
National Assembly Library of Thailand – Penal Code Overview
https://library.parliament.go.th/th/node/3380
Ongoing