The benefits of preventing smoking onset are well known, and even just delaying smoking onset conveys benefits. Tobacco control policies are of critical importance to low-income countries with high smoking rates such as Vietnam where smoking prevalence is greater than 55 % in young men between the ages of 25 and 45. Using a survey of teens and young adults, I conducted duration analyses to explore the impact of tobacco price on smoking onset. The results suggest that tobacco prices in Vietnam have a statistically significant and fairly substantial effect on the onset of smoking. Increases in average tobacco prices, measured by an index of tobacco prices and by the prices of two popular brands, are found to delay smoking onset. Of particular interest is the finding that Vietnamese youth are more sensitive to changes in prices of a popular international brand that has had favourable tax treatment since the late 1990s.