The present study was the first in Greece in which educational effectiveness theory constituted a knowledge base for investigating the impact of chemistry classroom environment in 10 Grade students' enjoyment of class. An interpretive heuristic schema was developed and utilised in order to incorporate two factors of teacher behaviour at classroom level, namely, "content coverage" and "cognitive teaching processes", with the patterns of a typology of classroom environments. The latter was drawn from data collected in Attica (a region in Greece) using a new and valid instrument, the How Chemistry Class is Working, while the Enjoyment of Chemistry Lessons scale was used to measure students' attitudes. A two-step cluster analysis revealed four patterns of the typology that were adaptable to the heuristic schema. The relationship between the patterns and students' gender, as well the variation in the level of students' enjoyment among the patterns, were explored. The traditional chemistry classroom environments were found to prevail and to be less enjoyable for the students, especially for the girls. It was found also that students enjoy chemistry lessons more when their goals are taken into account and they have an active role in learning process.