A wide variety of nonestablished treatments have been proposed as “cures” for the core features of autism and are used frequently despite having largely escaped scientific scrutiny. In contrast, a growing body of empirical evidence supports the use of a few forms of theory-based and empirically validated treatment for some aspects of the core features of autism. These include behavioral/psychoeducational interventions and specific forms of medication treatment, which can produce significant improvements in communication, social interaction, and problem behaviors that both maintain over time and generalize across settings. While there is no doubt that treatment and educational services for persons with autism have improved over the past 6 decades, it also appears that significant issues remain with respect to (1) the routine application of validated treatments for the majority of cases with autism, (2) the resistance to even validated forms of treatment for a substantial minority of cases with autism, and (3) the extent to which validated treatments effectively treat the specific core features of autism that are most disabling for persons with autism and their families. © 2004 Wiley-Liss, Inc. MRDD Research Reviews 2004;10:318–326.