BACKGROUND: Suicidality has been under-researched in autism spectrum disorders (ASD). Most studies have linked increased suicidality in ASD to psychiatric comorbidities such as depression. Here we investigated, from a neuropsychological and clinical standpoint, the relationship between core ASD symptoms, i.e., restricted behaviors and social and communication impairments, and the suicidal behaviors in an adult male individual with ASD, with no psychiatric comorbidities. CASE PRESENTATION: We report the case of a 21-year-old male with ASD who attempted suicide twice, in the absence of other psychiatric diagnoses. His behavior and communication skills were rigid. His suicidality was characterized by a rigid, detailed, and pervasive thinking pattern, akin to restricted interests. Consistently, from a neuropsychological standpoint, we found below-average planning and attention skills, and mind-reading skills were rigid and lacked spontaneity. CONCLUSIONS: Our case-study suggests that specific clinical and neuropsychological dimensions might be related to suicidal behaviors in ASD. Clinically, the repetitive and rigid suicide-oriented thinking of our patient was not part of a depressive episode. Instead, it followed a purely logical, inflexible, and pervasive reasoning pattern focused on a topic that fascinated him - i.e., suicide --, akin to restricted behaviors. From a neuropsychological standpoint, restrictive suicide-oriented thinking in our patient seems to be related to attention and executive anomalies that have been linked to repetitive and restricted behaviors in ASD. New tools need to be developed to assess persistent suicidal thoughts in this population, as they might be related to intrinsic features of ASD.