This study investigated the techniques used by secondary school Science Technology and Mathematics (STM) teachers in controlling undesirable behaviours in their classrooms. It adopted descriptive survey design in which 178 Anambra State teachers teaching STM subjects in senior secondary were involved in the research. Two sections of questionnaire used for data collection were validated and coefficients of internal consistency found to be 0.82 and 0.79. Data collected were analyzed using mean, percentage and t-test. Findings revealed that: Teachers always use traditional techniques science classroom; there is a significant difference in the mean rating of experienced and beginning teachers on their use of various techniques for controlling students' behaviours in favour of experienced teachers and male and female teachers do not differ significantly in their use of various techniques. It was recommended that beginning teachers should face orientation on use of the techniques.