The goal of the current study is to examine the role of poor migration planning as a moderator for the effects of two post-migration factors, namely acculturation stress and quality of life, on symptoms of depression. Using a random sample of 347 Hong Kong new migrants from a 1-year longitudinal study, we used multiple regression analyses to examine both the direct and interaction effects of poorly planned migration, acculturation stress, and quality of life on depressive symptoms. Although poorly planned migration did not predict depressive symptoms at 1-year follow-up, it did exacerbate the detrimental effect of the two post-migration factors, namely high stress or low quality of life (both also measured at baseline) on depressive symptoms at this stage. Our results indicate that preventive measures must be developed for new immigrants in Hong Kong, especially for those who were not well prepared for migration.