Objectives: More than half of older adults with major depressive disorder require extended treatment because of incomplete response during acute treatment. This study characterizes the effect of anxiety on remission during extended treatment for partial responders. Methods: Following 6 weeks of escitalopram 10 mg/day+depression care management (DCM), 124 partial responders (Hamilton Rating Scale for Depression (HRSD) scores of 11–14) were randomly assigned to receive extended treatment with escitalopram 20 mg/day+DCM with or without interpersonal psychotherapy (IPT) for 16 weekly sessions. Remission was defined as three consecutive weekly scores ≤7 on the HRSD. We assessed concurrent symptoms of anxiety using the Hamilton Rating Scale for Anxiety at pretreatment and after 6 weeks. We conducted Cox regression analysis of time to remission and logistic modeling of rates of remission. We also explored whether anxiety severity altered any impact of IPT. Results: Pretreatment anxiety was not associated with time to or rates of remission during 16 weeks of extended treatment. In contrast, more severe psychological symptoms of anxiety after 6 weeks of treatment was associated with both longer time to and lower rates of remission. However, there was no evidence that IPT showed any differential effects as a function of anxiety. Conclusions: In partial responders to 6 weeks of lower-dose escitalopram and DCM, planning for extended treatment should account for psychological symptoms of anxiety. Depression and Anxiety, 2010. © 2010 Wiley-Liss, Inc.