Introduction: Patients with cancer, have reported cancer-associated thrombosis (CAT), a distressing event in their overall illness. However, whether the clinical presentation of CAT; symptomatic versus asymptomatic, impacts illness perception is poorly elucidated. The aim of this study was to explore illness perception in patients with CAT, stratified by the clinical presentation. Materials and methods: In a qualitative design, we conducted a three-step workshop. Patients were included from a specialised cardiology care unit for oncology patients. Data analysis was performed using framework analysis. The analytic framework was based on the five components of illness perception: (1) identity of illness, (2) causal beliefs, (3) timeline beliefs, (4) beliefs about control/cure and (5) consequences. Results: Elleven patients with CAT participated in the workshop; five symptomatic and six asymptomatic. Whitin each category of illness perception following notions emerged (1) the identity of CAT was only tangible for symptomatic participants, (2) the aetiology was considered important information for symptomatic participants, which was in contrast to asymptomatic participants, (3) asymptomatic participant did not consider recurrent CAT a threat towards their health, (4) asymptomatic participants were prone to information overload, whilst information was imperative to the sense of control in symptomatic participants, (5) low molecular weight heparin treatment was accepted in symptomatic participants due to remission of symptoms. Conclusions: The clinical presentation of CAT (asymptomatic/symptomatic) proved essential to illness perception. These findings indicate that information level and communication within the medical consultation, should actively consider the clinical presentation of CAT in order to optimize management and compliance.