This study aimed to evaluate the prognostic significance of hemoglobin, albumin, lymphocyte, and platelet (HALP) levels at diagnosis in patients with multiple myeloma (MM). We retrospectively analyzed 450 patients diagnosed with MM between 2008 and 2023. The HALP score was calculated using pretreatment laboratory values of hemoglobin, albumin, lymphocytes, and platelets. Patients were categorized into the high and low HALP groups. Survival outcomes were analyzed using the Kaplan–Meier and Cox regression methods. Patients with HALP ≤ 27.68 had a significantly lower overall survival (OS) (median 50 vs 79 months, P < .001). Patients with low HALP scores had significantly shorter median OS and progression-free survival than those with high HALP scores ( P < .001). In the multivariate analysis, HALP ≤ 27.68 was independently associated with increased mortality risk (hazard ratio: 1.74; 95% confidence interavl: 1.32–2.29). The HALP score remained an independent predictor of OS. The HALP score is a useful, accessible, and cost-effective prognostic marker for MM, and may aid in risk stratification.