The purposes of this study were to examine how Turkish students perceived their biology classroom environment, how their perceptions compared to those of students in other countries, and what classroom learning environment profiles could be discerned in Turkish high school biology classrooms. Data were gathered from 1,474 high school students in four inner city schools, in Bursa, Turkey. A total of 11 biology teachers participated in the study with 52 of their classes. Data on students' perceptions of their learning environment were collected with the What Is Happening In this Class? (WIHIC) questionnaire. Results indicated that Turkish classrooms were perceived as being low in terms of Teacher Support and high in terms of Task Orientation. Six distinct classroom learning environment profiles were found: the "self-directed learning classroom", "task-oriented cooperative learning classroom", "mainstream classroom", "task-oriented individualised classroom", "low-effective learning classroom" and "high-effective learning classroom". The most common profile was the "mainstream classroom" for which all WIHIC scales had medium-high scores. (Contains 6 tables, 1 figure and 2 footnotes.)