The purpose of this research was to determine how Project-based Learning (PBL) influenced students’ behavioural, cognitive, and emotional engagement in a secondary Chemistry class. Most previous research studies refer to behavioural engagement when speaking of student engagement. This research was an attempt to distinguish between the various types of engagement and the use of different teaching pedagogies. The research compared twenty-five students’ behavioural, cognitive, and emotional engagement during two different chemistry units: one using PBL and the other without PBL. Levels of engagement were determined using checklists, surveys, attendance records, and test results from both units. Two of three instruments indicated a slight decrease in behavioural engagement during the PBL unit as compared with the non-PBL unit. Results were inconclusive in displaying an effect of PBL on cognitive engagement. Three instruments all showed different cognitive effects produced by using PBL. Emotional engagement remained high during both units. There was no indication that the use of PBL affected students’ emotional engagement.