BACKGROUND: Urolithiasis is among the most prevalent and possibly devastating diseases. It affects millions worldwide, and a cheap or rapid biomarker is required to diagnose it. Previous investigations revealed that inflammation has a role in the progression of urolithiasis patients, and an elevated neutrophil-to-lymphocyte ratio (NLR) value can be a valuable biomarker to ensure inflammation and, consequently, renal stones. This study was conducted to summarize the results of studies investigating the role of NLR in urolithiasis. METHODS: We systematically searched three main databases (Scopus, PubMed, and Web of Science) up to January 1, 2023. Our study was registered in PROSPERO (CRD42024500756). RESULTS: Ultimately, 33 studies were selected for this review article. Patients in either acute or subacute phase exhibited higher NLR levels than healthy controls. Also, patients in acute and subacute phases significantly differed regarding NLR levels. In addition, studies showed that NLR could predict sepsis and systemic inflammatory response syndrome (SIRS) among urolithiasis patients. In addition, evidence reported that NLR was helpful in the prediction of spontaneous stone passage among these patients. CONCLUSION: Our results support a reliable biomarker that is easily added into clinical settings to help predict urolithiasis patients' condition.