The presence of bone metastases (BM) in patients with lung cancer is indicative of a worse prognosis. The present study aims to investigate the risk factors associated with BM in patients with lung cancer. Patients with lung cancer admitted to the First Affiliated Hospital of Anhui Medical University between June 2019 and September 2021 were enrolled in this study. A nomogram was constructed based on the outcomes derived from univariate and multivariate analyses. Concordance index, calibration plots, receiver operating characteristic curves, and decision curve analysis were used to evaluate the nomogram. To substantiate the influence of monocytes on lung cancer BM, various assays, including cell co-culture, Transwell, wound-healing assays, and immunohistochemistry and immunofluorescence staining, were conducted. Statistical analyses were performed using SPSS 22.0 software and GraphPad Prism 7.0. A total of 462 eligible patients were enrolled, comprising 220 with BM and 242 without. Multivariate analysis revealed that histological type, medical history, monocyte percentage, and LDH (Lactate Dehydrogenase) and ALP (Alkaline Phosphatase) levels were independent risk factors for BM in lung cancer. Transwell and wound-healing assays indicated that co-culture with monocytes significantly enhanced the migration and invasion capabilities of A549 cells in vitro. Immunohistochemistry and immunofluorescence analyses demonstrated a noteworthy increase in monocyte infiltration in the primary lesions of patients with lung cancer with BM. In conclusion, this study successfully constructed and validated a precise, straightforward, and cost-effective prognostic nomogram for patients with lung cancer with BM.