Influenza viruses are a major health priority worldwide. Pigs can be infected with both human and avian strains, increasing the risk of emergence of new strains with pandemic potential. Therefore, risk-based surveillance for the early detection of new viruses is needed. In our study, we classified 22 commercial pig farms in northern Italy in terms of likelihood of influenza virus introduction, based on their biosecurity system and geographical location. We used a semi-quantitative risk assessment method to calculate risk priority codes, indicating increasing levels of risk for biosecurity criteria for the evaluated farms. Then, an overall risk index was calculated including a geographical risk indicator. The highest risk for all the farms regarded biosecurity related to buildings and access control, due to poor visitor control. Medium risk was obtained in fifteen farms for biosecurity related to personnel, with most of the farms compliant with training on biosecurity, but with some critical points related to the use of personal protective equipment. The method allowed the identification of farms at higher risk, which is crucial to implement risk-based surveillance and to apply strategies aimed at risk mitigation.