Background: It is unclear whether there is an association between chronotype and nonremission of depression, and whether the association is related to the confounding effect of insomnia. Method: A cohort of patients with major depressive disorder were assessed for chronotype (by Morningness- Eveningness Questinnaire [MEQ]), depressive symptoms, insomnia severity and clinical outcomes in a naturalistic follow-up study. Results: Of the 253 recruited subjects (age 50.8 ± 10.2 y; female: 82.6%; response rate 90.0%), 19.4%, 56.1% and 24.5% patients were classified as eveningness, intermediate, and morningness, respectively. Evening-type subjects had higher insomnia severity, more severe depressive symptoms, and higher suicidality. Eveningness was associated with nonremission of depression with an odds ratio (OR) of 3.36 (95% confidence interval [CI] 1.35-8.34, P