Purpose The impact of the COVID-19 pandemic on behavioral issues among those who have completed bariatric surgery (BS) is not well described in ethnically diverse populations. The aim of this study was to compare the impact of COVID-19 lockdown orders and after lockdown orders were lifted on substance use, mental health, and weight-related behaviors among a sample of post-BS adults. Materials and Methods A retrospective medical chart review identified BS patients from one university-based obesity medicine clinic and two BS practices. An online non-anonymous survey was implemented in two phases: during lockdown (April 1-May 31, 2020) and after lockdown orders were lifted (June 1, 2020-September 30, 2020) to obtain information about the COVID-19 pandemic's impact on BS patients. Results A total of 189 (during lockdown=39, post-lockdown=150) participants (90.4% female, mean age 52.4 years, SD 11.1, 49.8% non-Hispanic White, 30.6% non-Hispanic Black, 16.1% Hispanic) participated. Lockdown participants were more likely to have sleep problems (74.3% vs. 56.1%, P=.039) and feel anxious (82.0% vs. 63.0%, P=.024) versus post-lockdown participants. A majority (83.4%) reported depression in both lockdown/post-lockdown. Post-lockdown participants were more than 20 times more likely to report substance use compared those in lockdown (aOR 20.56, 95% CI 2.66-158.4).