Background: Winter swimming (WS), defined as brief immersion in cold or icy water, is gaining popularity in Poland as a recreational activity and potential health-promoting practice. Regular exposure to cold has been hypothesized to enhance immune function and reduce susceptibility to respiratory infections, yet empirical data on its relationship with influenza are limited. This pilot study aimed to assess the association between WS and the incidence of influenza and other respiratory infections among adults in Western Poland. Methods: Ninety-four participants (46 men, 48 women; mean age 39.0±12.0 years) were surveyed using a structured questionnaire assessing winter swimming frequency, physical activity, and the occurrence of influenza, common colds, and infection-related medication use. Statistical analyses included t-tests, chi-square, Fisher’s exact, Mann–Whitney U, and Spearman’s correlation tests, with significance set at p0.05). However, WS participants reported a significantly lower occurrence of common colds compared to non- swimmers (χ²=4.77, p=0.029), with the relationship remaining significant across swimming frequency cat egories (χ²=9.80, p=0.020). Physical activity levels were higher among WS participants (p=0.011) but not independently related to infection outcomes. Conclusions: These findings suggest that regular WS may confer moderate protective effects against mild upper respiratory infections, though its influence on influenza susceptibility remains unconfirmed. Larger longitudinal studies with laboratory-confirmed diagnostics are needed to verify these preliminary observations and clarify underlying mechanisms.