Liquid biopsy is the collection of circulating tumor cells (CTCs) and/or circulating tumor DNA (ctDNA) from non-solid biological tissue, primarily blood, for clinical purposes. In conjunction with next-generation sequencing, liquid biopsy is a non-invasive and rapid procedure, easily repeatable and highly sensitive, all advantages that make it an ideal tool to monitor the course of gynaecological malignancies, previously diagnosed on solid biopsy or surgical specimen. In the form of a blood draw, it may be performed at various time points throughout the treatment regimen to evaluate the appearance of resistant gene mutations, and also revealing the tumor's mutational burden and microsatellite instability status. Moreover, it can track minimal residual disease and predict tumor recurrence months or years before conventional imaging methods, allowing an early detection of cancer relapse and offering support to targeted therapy.