OBJECTIVE The aim of this study was to explore the beliefs, perceptions and representations of patients in order to identify the determinants of oral anticancer drugs adherence and to take action in current practice to improve patient support in digestive oncology. METHODS We constructed a semi-directed interview guide which aimed to explore the patient's relationship with medication, their health history, their experiences at the time of the announcement of treatment, their confidence, their fears, their motivations to adhere to their treatment and the constraints linked to their treatment. The data were analysed and discussed using a thematic approach. RESULTS Seventeen patients agreed to participate in the study. The median age was 60 years. Ten patients had colorectal cancer, 3 patients had hepatocellular carcinoma, 3 patients had gastrointestinal stromal tumour and 1 patient had neuroendocrine pancreatic tumour. We identified five categories of factors influencing adherence: demographic and socioeconomic, disease-related, treatment-related, care system-related, and patient representation and pathways' factors. A majority of patients emphasised the importance of family support in the adherence process and the convenience of per os treatment compared to other intravenous treatments. However, several negative determinants emerged such as the toxicity of the treatment, fears of forgetting to take the medication, difficulties with the galenic formulation and negative beliefs of the family. CONCLUSIONS This study demonstrates the need to address the different dimensions of the patient in order to understand his or her behaviour with regard to adherence and to identify the levers for improvement.