This paper represents a systematic review of peer-reviewed articles which included reports of parental dis/satisfaction about their child's autism spectrum disorder (ASD) assessment and diagnoses. Five themes emerged which are visualised in evidence maps: country comparisons of parental dis/satisfaction; factors which enhanced satisfaction; barriers which prohibited satisfaction; differences in national diagnostic methodology; and the chronology of diagnoses across countries. Evidence gaps indicate the lack of unified approaches to the diagnostic process; underrepresentation of such research showing a geographical spread; a lack of unified approaches to the diagnostic process; and where a significantly higher reporting of dissatisfied outcomes was documented. Results indicate that higher parental dissatisfaction is linked to those whose children had undergone the ASD diagnostic process, and those experiencing negative cultural stigmas prior to, or throughout, their child's ASD diagnosis.