Strategies to lessen the impact of pandemic influenza include behavioural modifications of the general public regarding medical care, personal hygiene and protection, and social distancing. We conducted a telephone survey of Beijing residents to evaluate potential behavioural changes in the general public in the event of an influenza pandemic occurring. We used a two-stage Mitofsky-Waksberg telephone survey of Beijing residents aged 15 years. The sample was weighted to reflect the 2000 census. We asked the respondents about their current healthcare-seeking behaviours for influenza-like illness (ILI), protective measures (personal hygiene, social distancing), and compliance with health authorities. We then asked what they would do during a hypothetical pandemic. We interviewed 256 Beijing participants in our study (response rate 56%). The percent of participants consulting a doctor for ILI rose from the current 41% [95% confidence interval (CI) 35-47] to 74% (95% CI 68-79) during a pandemic. Fifty-five percent (95% CI 48-62) of the participants would seek care from a more specialized hospital during a pandemic than currently. More than 90% of the participants reported already practising hand-washing or covering their coughs or sneezes during a non-pandemic period; this percentage changed little under a pandemic scenario. Compared to the current social distancing practices, more people would avoid crowded places (77% vs. 92%, P<0.01), use a mask outside the home (10% vs. 58%, P<0.01), and take time off from work or school (17% vs. 38%, P<0.01) during a pandemic. Moreover, 26% of the participants (95% CI 21-32) would stockpile food or water, and 55% (95% CI 49-61) would stockpile medicines. Some of the behavioural changes reported by Beijing participants might help to alleviate the damage caused by a potential pandemic. However, increased use of medical care at referral hospitals will further strain the healthcare system during a pandemic.