The article covers interpretation of the content of EU citizenship in the light of judgment of the Court of Justice of EU, C-34/09 Ruiz Zambrano v ONEm. This decision expands horizons of EU citizenship due to the term‘ the genuine enjoyment of the substance of rights conferred by the status of EU citizenship’. A refusal to grant a right of residence to a third country national with dependent minor children in the Member State where those children are nationals and reside, and also a refusal to grant such a person a work permit, has such an effect of depriving EU citizens of their rights. This was applied even that cross-border element was missing. Despite that the destiny and status of dependent children seem to play major role in the course of the case and maybe only situations of care will be granted in the future the same treatment of the Court like Zambrano. The Court created timeless basis for more uniform shape of Union Citizenship, free from reverse discrimination, to which may return later in its case law. The article compared also the content of Zambrano with later case of C-434/09 McCarthy.