Adultery Can Lead To Up To Three Years In Prison In Vietnam
Adultery-related violations can result in prison sentences of up to 3 years. | Source: Freepik
According to the Institute for Family and Gender Studies, infidelity accounted for 25.9% of divorce cases in Vietnam in 2023 – the second highest, just behind conflicting in lifestyles (27.7%).
In Vietnam, adultery is not just a moral issue but also a legal one. Under Decree No. 109/2026/ND-CP, effective from May 16, 2026, adultery-related violations are punishable by fines ranging from 5 million to 10 million dong ($190-380), twice the amount stipulated under previous regulations. In certain severe cases, the offence may result in criminal charges carrying a prison sentence of up to three years.
Adultery as an unlawful act
Legally, Vietnam follows a monogamous marriage system. Any conduct that violates this principle is considered unlawful and may be subject to administrative penalties or, in more serious cases, criminal prosecution.
Specifically, under Article 62(1) of Decree No. 109/2026/ND-CP, individuals who engage in adultery-related conduct may be fined between VND 5 million and VND 10 million (USD 190-380)
The following acts are considered violations:
- Marrying another person while already having a spouse;
- Marrying a person whom one knew is already married;
- Cohabiting with another person in a husband-and-wife relationship while already having a spouse;
- Cohabiting in a husband-and-wife relationship with a person whom one knew is already married.
In this context, “cohabiting as husband and wife” generally refers to living together and presenting oneself as a married couple without being legally married.
Compared with the previous Decree No. 82/2020/ND-CP, penalties for violations of Vietnam’s monogamy laws have been doubled. Previously, acts such as adultery or unlawful cohabitation were punishable by fines ranging from 3 million to 5 million dong ($113–189).
Meanwhile, the higher fine bracket of 10 million–20 million dong ($379–760) for more serious violations remains unchanged. These include coercing or deceiving another person into marriage or divorce, as well as exploiting divorce to evade property obligations or pursue purposes unrelated to the genuine dissolution of a marriage.
Penalties have also been increased for violations involving childbirth and reproductive practices, including the commercial use of assisted reproductive technologies, human cloning, and commercial surrogacy. Such offences are now punishable by fines of 10 million to 20 million dong ($379–760), double the previous level.
Beyond administrative sanctions, violations of the monogamy regime may also result in criminal liability if they cause serious consequences. For example, offenders may face prosecution if their conduct leads to the breakdown of a marriage and subsequent divorce, or if they reoffend after having already been penalised. The applicable penalties range from non-custodial reform for up to one year to imprisonment for between 3 months and 1 year.
In more severe cases – such as when the unlawful relationship contributes to the suicide of a spouse or child, or when the parties continue the relationship despite a court order requiring its termination–offenders may face prison sentences ranging from 6 months to 3 years.
How can you sue someone for adultery in Vietnam?
Administrative penalties are generally imposed only when the parties are found to be cohabiting with others as husband and wife, while criminal prosecution is reserved for cases involving serious consequences as defined by law.
In other situations, if a spouse discovers an extramarital affair, they may seek a unilateral divorce or pursue compensation through civil proceedings. However, such claims can typically be brought only against the unfaithful spouse, not the third party involved in the relationship.
In both cases, evidence plays a crucial role. Complainants are generally required to provide proof of the adulterous relationship, such as photographs, videos, publicly accessible messages, witness testimony, or evidence that the parties were living together as a couple. Criminal cases may additionally require evidence showing the serious consequences resulting from the relationship.
Importantly, any evidence must be obtained lawfully. Actions such as wiretapping, hacking into private accounts, or unlawfully accessing another person’s communications may violate privacy laws and could expose the accuser to legal liability.
The latest increase in fines reflects the government’s continued effort to protect the institution of marriage and uphold the country's monogamous family model. However, the burden of proof remains high.
According to Vietnamese law, cohabitation as husband and wife is proven by: having common children, being recognised as a couple by neighbours and the community, having common property, and continuing the relationship despite family/authority education. This is a really high threshold that often leads many disputes related to infidelity to be resolved through divorce proceedings rather than administrative or criminal sanctions.
As social attitudes toward marriage, relationships and personal freedom continue to evolve, Vietnam’s adultery law is an example of how private relationships can carry legal consequences.