Purpose <p>Examine the quality of evidence relating to the association of routine inflammatory biomarkers neutrophil-lymphocyte ratio (NLR), platelet-lymphocyte ratio (PLR) and monocyte-lymphocyte ratio (MLR) with symptoms, treatment toxicities, and quality of life (QoL) in people with advanced cancer.</p> Methods <p>Searches were conducted in MEDLINE, Embase, CINAHL and the Cochrane database to identify studies that investigated associations between NLR, PLR and MLR with symptoms, toxicities and QoL in people with advanced cancer. The evidence was graded as good, fair or poor through the application of the National Institute of Health (NIH) quality assessment tool. A narrative approach was used for data synthesis.</p> Results <p>Of the 38 studies reviewed, NLR was the most frequently investigated biomarker. Thirteen studies found no association between NLR and symptoms or treatment toxicities. Of the 25 that did, five provided good quality evidence linking NLR to immune-related adverse events (irAEs), chemotherapy-related haematological toxicities and insufficient oral intake. However, NLR cut-off values varied across studies. Ten studies reported an association between PLR and symptoms or treatment toxicities whilst six studies found no associations; one study found no association with MLR and symptoms or treatment toxicities.</p> Conclusion <p>Further research is needed to establish specific cut-off values of NLR to increase the utility of this biomarker in clinical practice. PLR and MLR warrant further investigation for association with symptoms, treatment toxicities and QoL.</p>