Due to a lack of substantial improvement in the outcome of patients suffering from oral squamous cell carcinoma (OSCC) during the past decades, current staging methods need to be revised. This disease is associated with poor survival rates despite considerable advances in diagnosis and treatment. The early detection of metastases is an important indicator of survival, prognosis and relapse. Therefore, a better understanding of the mechanisms underlying metastasis is crucial. Exploring alternative measures apart from common procedures is needed to identify new prognostic markers. Similar to previous findings predominantly for other solid tumours, recently published studies demonstrate that circulating tumour cells (CTCs) and disseminated tumour cells (DTCs) might serve as prognostic markers and could supplement routine staging in OSCC. Thus, the detection of CTCs/DTCs is a promising tool to determine the individual need for therapeutic intervention. Encouraging results and new approaches point to the future use of targeted therapies for OSCC, an exceedingly heterogeneous subgroup of head and neck cancer. This review focuses on summarising technologies currently used to detect CTCs/DTCs. The translational relevance for OSCC is highlighted. The inherent challenges in detecting CTCs/DTCs will be emphasised. Core tip: Oral squamous cell carcinoma (OSCC), among head and neck cancer, is related to poor survival rates despite considerable advances in diagnosis and treatment. Therefore, detecting tumour cell dissemination early and understanding the underlying mechanisms are crucial for predicting prognosis, relapse and survival. According to previous findings, circulating tumour cells (CTCs) and disseminated tumour cells (DTCs) might serve as prognostic markers to supplement routine staging and support determining individual therapeutic interventions. This review focuses on summarising the current knowledge about the detection of CTCs/DTCs with special emphasis on patients suffering from OSCC. The translational relevance of CTCs/DTCs and challenges for clinical application are highlighted.Wikner J, Gröbe A, Pantel K, Riethdorf S. Squamous cell carcinoma of the oral cavity and circulating tumour cells.