Research clearly indicates that early intensive behavioral intervention is an effective intervention for young children with Autism Spectrum Disorder (ASD). However little is known about the longitudinal development of these children. The purpose of this study was to examine the outcomes for a number of children with ASD following intensive behavioral interventions (IBI) prior to full-time integration in a mainstream setting having made significant gains following IBI. IQ, Adaptive Behavior Composites, Autism Index Scores, emotional and behavioral profiles and measures of parental perceived stress were obtained. Findings were mixed with some participants maintaining the gains they had made following IBI and others not. Results are presented and discussed with implications for future research outlined. (Contains 2 tables.)