Dong Hoi in Vietnam is generally safe for solo female travelers. Like anywhere, it's important to maintain your usual vigilance and awareness, particularly at night. Petty crime such as pickpocketing can occur but is not very common. Local people in Dong Hoi are friendly and helpful, making the area feel safe and welcoming. As always, it is highly recommended to respect local customs and dress modestly. Many locals do not speak English, which might be a challenge if you need help. Overall though, Dong Hoi is a tranquil city with low rates of crime.