Background:
Romania has a high prevalence of adult smoking, necessitating effective cessation interventions like the STOP FUMAT program. Recent global events, like the COVID-19 pandemic, may influence smoking behavior and cessation attempts, posing challenges for public health interventions.

Objectives:
This study aims to investigate the impact of the COVID-19 pandemic on treatment adherence, smoking cessation outcomes, and reasons for resuming smoking among participants in the STOP FUMAT program.

Methods:
We conducted a retrospective cohort study of 98 participants who enrolled in the program between 2020 and 2021, using a phone-based survey. Variables of interest included demographic factors, health status, smoking behavior, completion of the smoking cessation treatment, and perception of the pandemic's impact on smoking behavior.

Results:
Treatment completion was not significantly associated with demographic or health characteristics. However, those who completed the treatment were more likely to believe in its efficacy (68.6% vs. 47.8%, p=0.038). Most patients resumed smoking within three months of treatment, with a significant difference between completers (42.1%) and non-completers (67.5%, p=0.014). Stress and the COVID-19 pandemic were major reasons for smoking resumption, and those who felt affected by the pandemic expressed a stronger desire to re-engage with the program.

Conclusions:
The pandemic did not significantly impact treatment adherence, but it influenced patients' smoking behavior and perceptions. The study underlines the importance of addressing stress-related triggers for smoking and communicating the benefits of treatment, particularly during global crises like the COVID-19 pandemic.