In the context of far-reaching policy reforms on immigration and integration in Germany, there has been a growing interest in better statistical and scientific information about the underlying migration and integration processes. The article argues that, in addition to the necessary efforts to supplement existing statistical systems and set up new surveys, there is a chance to provide more in-depth information through more exhaustive analyses of data already available. The main aim of this contribution is to test whether the information on spatial mobility recorded in the German Microcensus since the early 1980s is a reliable, valid source for migration studies. In addition to a discussion on general methodological features of this official annual population survey, the paper compares estimates of the international migration of German citizens based on the Microcensus with reference data drawn from German population registers. Differentiating the results of other recent contributions on this topic, the analyses show that migration scholars should make more use of the question on "place of residence twelve months ago" when estimating migrants' socio-economic characteristics and motives. It argues that the German Microcensus on its own, as well as in combination with other similar official population surveys from other countries, provides a valuable data source for nationally- and internationally-comparative migration studies.