Observational learning (OL) is critical for the acquisition of many skills, consequently allowing for success within mainstream educational settings as it maximizes learning opportunities and allows for the acquisition of novel information without explicit teaching. However, research suggests that OL may be limited in children diagnosed with autism spectrum disorder (ASD). The purpose of the present study was to determine if two participants diagnosed with ASD and lacking an OL repertoire could be taught new sight words as a result of observing a confederate make correct and incorrect responses to these stimuli, in which no error correction was observed. Furthermore, the current study investigated the degree this discrimination skill could be generalised to stimuli not associated with training. Relatively strong findings were found for one of the two participants, with results showing that this participant responded correctly more consistently following correct observational trials, compared to incorrect observational trials. The second participant’s negative findings are discussed in relation to overelectivity and prompt dependency. The main concluding implication of this study suggests that exclusionary learning may be an additional prerequisite of OL.