Given the increasing rates of autism, identifying prompting procedures that can assist in the development of more optimal learning opportunities for this population is critical. Extensive empirical research exists supporting the effectiveness of various prompting strategies. Constant time delay (CTD) is a highly implemented prompting procedure that has been researched widely, and demonstrated as effective and efficient. A second approach, flexible prompt fading (FPF) has not been empirically tested but has been a part of numerous behavioral studies [Lovaas, O. I. (1987). Behavioral treatment and normal educational and intellectual functioning in young autistic children. "Journal of Clinical and Consulting Psychology, 55", 3-9; Soluaga, D., Papovich, S., Leaf, J., McEachin, J., Leaf, R., & Taubman, M. (2003). "Instruction in social competencies utilizing a social skills taxonomy for persons with autism (databased presentation)". Paper presented at the National Conference of the National Association for Behavior Analysis, San Francisco, CA]. The purpose of this study was to compare the effectiveness and efficiency of CTD and FPF in teaching receptive skills for five children with autism. A parallel treatment design demonstrated that, overall, the FPF procedure produced better results in terms of individual mastery of targets and global mastery of all targets and comparable results were seen in terms of efficiency for the two prompting procedures. (Contains 4 tables and 2 figures.)