D-dimer is a fibrin degradation fragment widely assessed in clinical practice as an indirect laboratory marker of coagulation activation and subsequent fibrinolysis. Its measurement plays a pivotal role in the screening, prognosis, and monitoring of clinical conditions associated with haemostatic dysfunction, including venous thromboembolism, disseminated intravascular coagulation, sepsis, neoplasms, severe inflammatory states, autoimmune diseases, pregnancy, and obstetric complications. However, interpretation of D-dimer levels requires careful contextual analysis due to its low specificity and the variability among available laboratory methods.

Given its broad clinical applicability and the uncertainties regarding diagnostic accuracy, we conducted a scoping review to map and synthesise the available evidence D dimer use as a labroatorial biomarker, considering the clinical contexts of application, quantification methods, limitations, and future perspectives.

The review was conducted in accordance with the methodological guidelines of the Joanna Briggs Institute and the PRISMA-ScR protocol. The search strategy was applied across the Medline/PubMed, SciELO, LILACS, and BDENF databases, with no temporal restriction, including publications in Portuguese, English, and Spanish. Grey literature was searched via Google Scholar, with the first 100 results reviewed, without filters. Study selection was performed in two phases by two independent reviewers using the online platform Rayyan®. In the first phase, titles and abstracts were screened based on predefined eligibility criteria. In the second, full texts were assessed using the same criteria. Discrepancies were resolved through consensus.

A total of 156 studies were included and categorised into 18 distinct clinical contexts. The findings reveal widespread use of D-dimer, highlighting its high sensitivity in excluding thrombotic events and its prognostic utility in conditions such as sepsis, trauma, and cancer. Nonetheless, important limitations were identified, including the lack of standardisation in quantification methods, the influence of pre-analytical variables, heterogeneity in cut-off values, and low specificity in non- specific inflammatory conditions. Furthermore, few comparative studies between laboratory methodologies were found, along with a limited number of multicentre investigations exploring the integration of D-dimer with other biomarkers. In conclusion, although extensively applied in clinical practice, D-dimer should be interpreted with caution and always together with complementary clinical and laboratory data. There is an urgent need for technical standardisation and the production of more robust evidence to enhance its safe and accurate clinical applicability.