Neuraminidase inhibitors (NAI) are effective anti-influenza antiviral treatment. During their use in experimentally infected patients, it has been shown that the viral load detected in the nasal fluid is decreasing significantly faster than in non treated patients. During clinical practice, the emergence of NAI-resistant strains has been observed. These strains remain rare, but their emergence seemed to be related to the mis-use of the NAI products (insufficient duration or dosage). This observation as well as the detection of NAI-resistant viruses in the community raises concerns about putative emergence of resistant clones in the specific context of a pandemic, when the use of NAI will be very large in the aim of reducing transmission, and subsequently the impact of the emerging virus.