Already in their early childhood, bilingual children face challenges to which their monolingual peers are not exposed, such as issues of identity and cultural affiliation. The acquisition of Hungarian and Croatian could be further hampered by profound differences at the morphological, semantic, orthographic and phonological levels. Adverse environmental factors could, in extreme cases, even lead to double semilingualism, which would jeopardize future education and overall well-being of the children. Given that early childhood is crucial for the future and general well-being of children, we can by no means neglect the role of a quality kindergarten environment. To improve the quality of pre-school education of bilingual children, it is crucial to establish the initial state of language competences of children of that age. The paper investigates the differences in the knowledge of lexemes in Hungarian-Croatian or Croatian-Hungarian bilingual preschool children, in respect of the place of residence, family context, and kindergarten environment. The participants of the conducted research are children aged three to seven years (n=27), enrolled in those preschool institutions in the City of Zagreb and Osijek-Baranja County where Hungarian language is being used in educational groups. The task of recognizing and naming images according to Legac, Kiš-Novak, and Lapat (2020) is being used as a measuring instrument. Parents (n=27) also participated in the research, filling in a sociolinguistic questionnaire, while educators (n=6) provided data on the use of these languages in their work with children. The objectives of the research are to determine the results in the knowledge of some basic concepts in Croatian and Hungarian and to investigate the differences in the knowledge of these languages regarding parental educational strategies and the frequency of educational activities in these languages. An insight into the obtained results reveals that the children attending the Zagreb kindergarten demonstrated more success in naming terms in the Hungarian language. In contrast, the children from the Osijek kindergarten achieved better results in their knowledge of the Croatian language. The results also confirmed the hypothesis that older children would have better results (r=0.5, p<0.01), while the three remaining hypotheses proved to be untrue.