This study investigated middle school students' behavioural, emotional, cognitive, and agentic engagement in science in relation to self-efficacy and learning environment variables. Learning environment variables addressed in the study were shared control, student negotiation, promoting mutual respect, and teacher feedback. Participants of the study were 407 middle school students attending two public schools in the eastern part of Turkey. Path analysis showed that self-efficacy and teacher feedback were positive predictors for all aspects of student engagement while shared control predicted most of the engagement aspects other than emotional engagement. Promoting mutual respect was positively linked to behavioural engagement whereas student negotiation was not related to any of the engagement components. Amount of explained variance in engagement components ranged from 21% to 33%. Additionally, student negotiation, promoting mutual respect, and teacher feedback positively predicted self-efficacy and learning environment variables together explained 23% of variance in self-efficacy.