Purpose: Skeletal metastases are a common problem in breast cancer patients. Identifying new prognostic factors can improve survival estimations and guide healthcare professionals in therapeutic decision-making. Our study aimed to determine the prognostic value of inflammatory biomarkers such as neutrophil-to-lymphocyte ratio (NLR), lymphocyte-tomonocyte ratio (LMR), and C-reactive protein/albumin ratio (CAR) in patients with breast cancer skeletal metastases. Patients and Methods: Clinical data from 212 patients with breast cancer skeletal metastases were retrospectively analyzed. The optimal cutoff values of each inflammatory biomarker were extracted from the receiver operating characteristic (ROC) curves. Patients were divided into high-value and low-value groups according to the cutoff values of NLR, LMR, and CAR. We investigated the relationship between inflammatory biomarkers and clinicopathological characteristics. The Kaplan-Meier method was used to measure progression-free survival (PFS) and overall survival (OS). The survival difference was compared by the univariate analysis. Cox multivariate regression analysis was performed to identify independent prognostic factors. Results: The median age of the patients was 55 years, and the median follow-up was 45 months. LMR<3.43 (P<0.0001), NLR≥2.48 (P<0.0001), and CAR≥0.34 (P=0.035) were found to be associated with worse PFS in the univariate analysis. Meanwhile, LMR<3.43 (P<0.0001), NLR≥2.48 (P<0.0001), and CAR≥0.34 (P=0.025) were linked to the poor OS. The multivariate analysis revealed that NLR≥2.48 (HR 2.044, P=0.007) and LMR<3.43 (HR 0.532, P=0.012) were independent prognostic factors for OS; LMR<3.43 (HR 0.501; P=0.006) and NLR≥2.48 (HR 1.971, P=0.011) were similarly prognosticating worse PFS. Radiotherapy to the affected bone and ER (+) was favorable for the prognosis of breast cancer skeletal metastases. The number of involved sites of bone metastases>3 was adverse for PFS. Conclusion: LMR<3.43 and NLR≥2.48 were independently associated with worse prognosis of patients of breast cancer skeletal metastases.