The purpose of this study was to examine pre-service teachers' treatment integrity (TI) in the use of constant time delay (CTD) and simultaneous prompting (SP) while teaching discrete and chained behaviours. A descriptive research design was used. A total of 28 pre-service special education teachers (16 females and 12 males), whose ages ranged from 20 to35 years, participated in the study. The data were collected by applying four different observation and self-assessment checklists to video recordings. A descriptive analysis was conducted. The findings reveal that pre-service teachers implemented CTD and SP in discrete behaviours with higher TI than the CTD and SP in chained behaviours. Recommendations for future research and practice are provided.