This dataset contains relational data (networks) from classrooms in Moravia in the Czech Republic. The relational data were acquired with a standardized Czech pen-and-paper sociometric questionnaire designed for assessment of likeability between students in classrooms – the questionnaire originally had a rating scale for each student where each student was able to identify two degrees of likeability and two degrees of antipathy towards another student – this was removed in the present data and only presence of likeability or antipathy is noted. The data is intended to be used for social network analysis.