Suicide as a cause of death among adolescents and migration as a component of population have been growing in importance. Very little research has been conducted on the connections between migration and suicidality among adolescents in Hong Kong, and so is the aim of this article. It uses census and registration data to study suicide mortality, and sample survey data collected for this purpose to investigate suicide attempt, suicide ideation, and self-injurious behavior. Relations between suicidality and socio-demographic/psychological factors replicated those found in the literature. Duration of residence was found important for the study of suicide among migrants. In both the bivariate and multivariate analyses, although the suicidality levels for short-duration (less than 10 years) adolescent migrants were very much lower than the local-born counterparts, those for the long-duration (10 years or more) migrants were very much higher. The findings support the Healthy Migrant Hypothesis and other related hypotheses in migrant mortality studies. They also reveal, in the light of the Integration Theory of Suicide, the problem of migrant integration into the host culture and society, an important social problem for the government to solve. [Copyright of Death studies is the property of Routledge. Full article may be available at the publisher's website: http://dx.doi.org/10.1080/07481180600993144]