<p>Coastal areas globally face mounting challenges due to increased human activities, resulting in substantial environmental impacts on beaches and marine ecosystems. This study delves into the influence of peak tourist seasons on cigarette butts (CBs) contamination along an urban beach, specifically Mar Grosso beach boardwalk in Laguna, Brazil. The study period spanned peak tourist seasons (PS) and off-seasons (OS), with data collected on CBs density and degradation levels across different areas of the boardwalk. A total of 6621 CBs were collected from the beach boardwalk along Mar Grosso beach, resulting in a density of 0.50 CBs/m². It is worth noting that higher CBs densities were observed during the PS (0.38 CBs/m²), particularly in areas with urban structures that attract human presence, despite the presence of waste collection bins. Stages II and III of CBs degradation were the most abundant along the Mar Grosso beach boardwalk. Moreover, our research indicates a severe pollution index for the Mar Grosso Beach boardwalk during the PS season in all analyzed sectors (18.25–31.60). The study underscores the urgent need for improved waste management practices, environmental education, and policy interventions to curb CBs contamination and its adverse impacts on coastal ecosystems and public health.</p>