Smoking has been one of the great threats to health in recent years, being strongly correlated with multiple negative health consequences, including lung cancer. Recent research suggests that artificial intelligence chatbots can be effective in persuading healthy behavior change. However, these chatbots usually rely on persuasive techniques to achieve their goal. Such techniques depend on identifying and meeting users' needs to be effective. To help improve understanding of the domain of healthy behavior change, we proposed a study which analysed the needs of daily smokers as they emerged from their interactions with a chatbot specifically designed to help them quit. The study performed a thematic analysis on users' free-text feedback, from which a set of 8 themes that directly correspond to 8 different needs were observed. The user needs were correlated with their genders, ages and highest completed education levels. While most of the results indicate that there is no significant correlation between the needs and user characteristics, which suggests that user needs are evenly distributed, certain correlations were highlighted for further analysis.