Questions have been raised as to whether the patterns of thoughts and behaviours experienced by individuals with autistic spectrum disorders (ASD) can be indicative of comorbid obsessive compulsive disorder (OCD). The current study aimed to compare the experiences of adults with ASD or OCD and healthy controls (HC) in terms of the symptoms experienced and the associated emotions and responses. Associations between autistic traits and OCD severity were explored. A cross-sectional design utilising MANOVA, ANOVA and correlation was employed. Methods: Eighteen participants with ASD, 20 with OCD and 19 healthy controls completed self-report measures and interviews assessing IQ, comorbid diagnoses, OCD symptoms, autistic traits and emotions and responses associated with obsessional thoughts. Participants with ASD scored significantly higher than healthy controls in terms of OCD severity and also number of obsessions and compulsions and associated distress. While the OCD and ASD groups did not differ significantly on OCD severity, the OCD group reported significantly higher levels of sadness, worry, shame, guilt and disapproval triggered by obsessions. The ASD and healthy control groups were largely comparable on these factors. Associations were found between OCD severity and particular domains which are typically impaired in ASD, including social skills, attention switching, communication and imagination. Findings suggest that OCD symptoms may be common and a source of distress in individuals with ASD, thus perhaps warranting psychological intervention. Further research into the exact nature of this distress and how this can be assessed is required.