A household survey and a census can be combined to estimate a poverty map for small areas. Ideally, the survey and the census should be conducted in the same year. In several empirical applications, however, survey and census years can be different, which might make poverty estimates biased. Using data from the Vietnam Household Living Standard Survey 2002 and the 1999 Population and Housing Census, the present paper produces a 2002 poverty map for Vietnam and describes the biases when the survey and census years are not coincident. It is found that poverty estimates from the poverty mapping method taking into account the time difference between the survey and the census are quite close to survey-based estimates, at least at the regional level. Copyright 2009 The Author. Journal compilation 2009 East Asian Economic Association and Blackwell Publishing Ltd..