The open and free practice of religion in Viet Nam continues to be a complicated issue to describe or assess. In short there’s good and bad as highlighted in the following quote:
“To be sure, the freedom to practice one’s faith or beliefs in Vietnam has come a long way since the dark days following the 1975 communist takeover. Many individuals and religious communities are able to exercise their religion or belief freely, openly, and without fear. To its credit, the Vietnamese government has made a concerted effort to improve conditions in a number of ways. For example, the government is creating more space for religious organizations to conduct charitable work and taking steps to improve relations with the Vatican. In many communities, religious organizations and local officials get along well, with little to no interference by the latter. And the government solicited limited public input on its religion law, a move that would have been unheard of just a few years ago.
Nevertheless, the Vietnamese government’s complicity in or indifference to egregious violations of religious freedom in many parts of the country is deeply troubling. In some areas, local authorities harass and discriminate against religious organizations that do not have government recognition, and in others, they threaten religious followers with eviction from or demolition of their places of worship or other religious buildings—in some instances carrying out these threats. Law enforcement officials continue to detain, arrest, and/or imprison individuals due to their religious beliefs or religious freedom advocacy. The scope and scale of these violations make clear that Vietnam still is a long way from respecting the universal right to freedom of religion or belief as defined by international law and covenants.”
That quote comes from the U.S. Commission on International Religious Freedom and their report from earlier this year, Religious Freedom in Vietnam: Assessing the Country of Particular Concern Designation 10 Years After its Removal. Also from the USCIRF from earlier this Spring is the 2017 report on religious freedom. You can view an excerpt specific to Viet Nam of this annual report here and the report in full here.