To investigate the efficacy of recombinant human endostatin (rh-Endo) plus neoadjuvant chemotherapy (NACT) for osteosarcoma (OSA) and its influence on serum vascular endothelial growth factor (VEGF) and matrix metalloproteinase-9 (MMP-9). The case data of 141 OSA patients presented to the North District, Xiangyang Central Hospital Affiliated to Hubei University of Arts and Sciences from January 2018 to June 2019, were analyzed retrospectively. Patients receiving NACT (methotrexate + ifosfamide + adriamycin) were assigned into the control group (CNG; n = 65), while those treated with rh-Endo plus NACT were included in the combination group (CMG; n = 76). The following aspects were compared: clinical efficacy, serum tumor markers, serum VEGF and MMP-9 contents, inflammatory factors, incidence of adverse reactions, limb function scores at 6 months of follow-up, and prognostic quality of life (QOL). A statistically higher overall response rate (ORR) was determined in CMG versus CNG (84.2% vs. 64.6%, P < 0.05). The pretreatment serum bone alkaline phosphatase (BALP), insulin-like growth factor (IGF)-1, serum amyloid A (SAA), VEGF, MMP-9, C-reactive protein (CRP), tumor necrosis factor (TNF)-α, and interleukin (IL)-10 levels differed insignificantly between the two cohorts (P > 0.05); while except IL-10 that showed increased expression in both cohorts and was comparatively higher in CMG, the other 8 parameters reduced in both cohorts after 2 weeks of drug withdrawal, and the reduction of each parameter was more significant in CMG (P < 0.05). The total adverse reaction rate was 30.2% in CMG, which was higher than that of 36.9% in CNG, albeit without a statistical difference (P > 0.05). An evidently higher 2-year survival rate was determined in CMG (P < 0.05). rh-Endo plus NACT is more effective than NACT alone in the treatment of osteosarcoma, which can validly restore the balance of vascular endothelial cells, reduce inflammation, and is worth promoting in clinic.