The paper analyzes ethnic data collection pertaining to criminal justice in Hungary. It shows that Hungary's approach to resist ethnic data collection by law enforcement authorities is not a good policy and it causes severe constitutional problems in other, non-criminal legal circumstances, where ethnic data is used in the context of additional rights and affirmative protection provided for ethno-national minorities. The paper follows a twofold analysis. First, it sets forth general problems relating to ethnic data collection, including a brief analysis of a uniquely Hungarian constitutional institution, the minority self-government structure. The focus of scrutiny then shifts to the criminal justice system, in particular the analysis of policing of racially motivated crime, and the question of police ethnic profiling.