The aim of the research is to describe in detail the relation of need for cognitive closure of student teachers (pre-service teachers) and their classroom management strategies used on their long term teaching practice in lower secondary classes in the Czech Republic. The research is based on an integrated mixed methods design (Creswell & Plano Clark, 2011). The main, qualitative part is designed as field research based on ethnographic research design. Its aim is to describe conceptions (via interviews and reflective teaching diaries) and use (via observation with video recordings and its transcription) of CMS of student teachers. Need for cognitive closure (NFC) affects the use of classroom management strategies (CMS) of student teachers. Student teachers with higher NFC use more CMS oriented at rules and leading the classroom. The higher the NFC is the more the student teachers prefer teaching in frontal settings, deviate less from their lesson plan; require the student´s discipline more strictly, and insists on student´s following the rules. The students orientation on rules and directing the classroom is higher with larges classrooms. Qualitative data deepen typology of student teachers classroom management strategies.