In order to contain a measles outbreak in a German asylum-seekers' shelter, serological testing of all residents was performed, followed by selective vaccination of those with negative test results/not tested. In this paper we describe the outbreak epidemiologically and then compare the implemented strategy with a hypothetical mass vaccination of all individuals unvaccinated or with unknown vaccination status born after 1970 as recommended by the German Standing Committee on Vaccination in terms of potentially avoided cases, logistics, and costs. Three hundred (70%) residents participated in the serological testing, of which 39 (13%) were seronegative. In total, 144 individuals were eligible for vaccination, while a mass vaccination would have targeted 359 persons. However, serological testing was time- and personnel consuming and revealed several logistical problems. Its costs amounted to €90 000, double that of mass vaccination that additionally might have avoided three of the eight cases. Mass vaccination seems the preferred measure for measles outbreak control in such settings.