There is no reported investigation comparing concordance in attitudes and beliefs about autism spectrum disorder between parents of children with autism spectrum disorder and scientists who research autism spectrum disorder. To investigate the level of concordance between these groups on causes of autism, priorities of research, perceived stigma, and disclosure of genetic test results, telephone interviews were conducted. Parents (n?=?502) were recruited from the Simons Simplex Collection, and research scientists (n?=?60) were recruited from investigators funded by the Simons Foundation. Response rates were notable (parents 91%, scientists 80%). Parents and scientists differed significantly regarding beliefs of the likely major cause of autism (p?=?0.007) and priorities for further research (p?<?0.001). Scientists believed in genetic causes while many parents believed in vaccines as the cause of autism. Parents (37%) were more likely to hesitate vaccinating their child (p?<?0.001). In contrast, there was strong concordance regarding extent of perceived stigma (95% vs 92%) and preferences for disclosure of genetic test results, including incidental findings. While scientists believed communication important, paradoxically fewer than half reported it important for scientists to communicate directly with parents. Better communication between parents and scientists should improve mutual understanding and ultimately the health and well-being of children with autism spectrum disorder and their families.