We sought to explore the prognostic role of the hemoglobin, albumin, lymphocyte, and platelet (HALP) score on survival outcomes in patients with solid tumors by performing a systematic review and meta-analysis.PubMed, EMBASE and Web of Science were searched for relevant articles through 02 Nov 2022. Hazard ratios (HRs) with 95% confidence intervals (95% CIs) were extracted and pooled to assess the association of the HALP score with survival outcomes in solid tumors using Stata 15.0. The primary outcome was overall survival (OS), and the secondary outcomes were cancer-specific survival (CSS) and progression/disease/recurrence-free survival (PFS/DFS/RFS).A total of 28 studies (31 cohorts) comprising 13,038 patients were enrolled. A low HALP score was associated with decreased OS (HR, 1.61; 95 % CI, 1.44-1.81; P < 0.001), CSS (HR, 1.80; 95 % CI: 1.54-2.09; P < 0.001) and PFS/DFS/RFS (HR, 1.61; 95 % CI: 1.45-1.80; P < 0.001). The prognostic value of HALP on OS was observed across various tumor types and tumor stages. meta-regression found that tumor stage was the major source of the heterogeneity for OS.A low pretreatment HALP score is a reliable and negative prognostic biomarker for survival outcomes in patients with cancer.Copyright © 2022 Elsevier B.V. All rights reserved.