This study assessed parents' first concerns about their autistic child. This information was categorized so that it could help healthcare professionals improve early detection of autism. We designed a questionnaire using an open-ended format, and 459 questionnaires were completed by parents to assess difficulties encountered in obtaining a diagnosis for their child. Answers about their first motive of concerns were categorized and compared with regards to age, gender, birth order, age of onset, delay in seeking professional advice, and delay in diagnosis. Concerns about social development or autistic behaviors were frequent, but not exclusive. Parents were divided into three clusters of concerns: (a) an "early awareness group": which included motor problems and passivity (14.6 months); (b) ''intermediate awareness group'': included emotional, hyperactivity, and sleep problems (15.3 months); and (c) a ''later awareness group'': which included communication problems, poor social interaction, and autistic-type behaviors (22.3 months). Parents who noticed general concerns not specific to autism were worried earlier, but received a later diagnosis. We suggest that motor problems, and/or emotional problems, and/or the level of a child's activity should encourage frontline professionals to seek autistic symptoms in infants. (Contains 3 tables and 3 figures.)