Diagnostic assessment for autism spectrum disorder (ASD) is a complex and often stressful process for parents. This systematic review synthesized results of 26 articles that reported on factors related to parental (dis)satisfaction with the diagnostic process for ASD. The results are described in terms of factors related to satisfaction and those related to dissatisfaction (with some overlap between these), in the context of temporality within the diagnostic process. Subsequently, factors are described in terms of those that can be directly influenced by clinicians and those that are outside of direct clinician control. Implications of the findings and directions for future research are provided.