Objective: To understand the obstacles that reduce accessibility to the diagnosis and treatment of autism spectrum disorder (ASD). Literature review: ASD is a disorder characterized by difficulties in social interaction, impairments in communication and restricted patterns of behavior. Its diagnosis is clinical, based on behavioral observations and the patient's history and on criteria defined in the Diagnostic and Statistical Manual of Mental Disorders (DSM – 5). Treatment includes pharmacological and behavioral approaches. However, the difficulties and challenges found in the literature include the symptomatological heterogeneity of ASD, the need for training health professionals and a more accurate assessment through a multidisciplinary team. Late diagnosis or its absence can lead to unfavorable outcomes in adult life, such as: anxiety, depression, and difficulty in interpersonal relationships. Recent studies include the use of specific biomarkers and innovative therapies that are not yet accessible. Final considerations: Early diagnosis and appropriate treatment are ideal for improving the quality of life of individuals with ASD. The importance of the doctor and new studies to improve therapeutic choice in ASD is also highlighted.