[Objective] This study aims to explore the clinical significance of measuring serum β-galactoside-binding protein-3 (LGALS3) in non-traumatic osteonecrosis of the femoral head (NONFH). [Methods] The study included 84 NONFH patients treated at Linyi People''s Hospital from April to September 2023 as the necrosis group, and 78 healthy individuals undergoing physical examinations in the same period as the control group. Serum LGALS3 levels were measured using enzyme-linked immunosorbent assay in both groups, and clinical data were collected for analysis, including gender, age, BMI, smoking status, etiology, affected side(s), VAS score, Harris score, degree of collapse, and ARCO staging. The study compared and analyzed the concentrations of LGALS3 and the relationships with these clinical parameters in both groups. [Results] The concentration of serum LGALS3 in the NONFH patient group was significantly higher than that in the healthy group (P<0.05). In the stratified comparison of various indicators with serum LGALS3 levels, no significant differences were observed in smoking status and etiology. The LGALS3 levels in bilateral osteonecrosis were significantly higher than in unilateral cases (P<0.05), and higher in the collapsed group compared to the non-collapsed group (P<0.05). The levels of LGALS3 increased progressively from ARCO stage I to IV, with statistically significant differences (P<0.05). [Conclusion] Serum LGALS3 levels can reflect the severity of NONFH and may serve as a potential biomarker for early diagnosis of NONFH.