Background: A diagnosis of childhood autism can be an extremely stressful experience for parents, but little is known concerning paternal perceptions of the process. Methods: This study investigated father perspectives on a diagnosis of autism, through an online survey. Results: An analysis of 184 replies to an open-ended question identified the following themes: strong initial emotional response and a range of immediate anxieties about the future, struggle to gain a diagnosis; anger in response to insensitive delivery of diagnosis together with insufficient information at the time and lack of support afterwards. Conclusion: Fathers experienced a range of significant challenges during a diagnostic process in which most felt unsupported. Service provision should be more gender-differentiated, taking into account of the particular needs and perspectives of both mothers and fathers at this critical juncture in family life.