ABSTRACT Background: Tics are common in people with autism spectrum disorder ( ASD ). However, their phenomenology and characteristics have not been studied in detail. Methods: Based on video sequences of 21 adults with ASD without intellectual disability and 16 adults with Gilles de la Tourette syndrome ( GTS ), tic severity, tic repertoires, and tic awareness were determined. Results: Ten ASD and all GTS participants had tics during video recordings. The ASD group had significantly fewer tics, compared to GTS . Tic distribution and tic repertoires were comparable, but more restricted in ASD . All GTS participants, but only 5 of the 10 ASD participants, were aware of their tics. Conclusions: Tics are common in adults with ASD . They are indistinguishable from tics in GTS and are similarly distributed, but less severe. Tic awareness is limited in ASD .