Aim: The aim of this study was to compare serum levels of biochemical markers of bone metabolism – osteocalcin (OC) in correlation with bone metastases found during whole-body bone scintigraphy in patients with lung cancer. Material and Methods: The serum levels of OC as a bone formation marker were determined in 60 patients (46 male, 14 female, mean age 66.65, range 50–84 years) with lung cancer (51 non-small-cell lung cancers – NSCLC and nine small-cell lung cancers – SCLC) and correlated with the presence of bone metastases detected by whole-body bone scintigraphy (hybrid system SPECT/CT: BrightView XCT, Philips Healthcare). Whole-body bone scintigraphy results were compared with OC for each patient with lung cancer and for person from control group of 10 persons (two males, eight females, mean age 52.3, range 34–67 years) with out malignant disease. Results: By whole-body bone scintigraphy, bone metastases were found in 15 cases (25%), probably in 11 cases (18.33%) and 34 patients (56.67%) were without bone metastases out of 60 patients with lung cancer. The serum levels of OC were above ref erence range in five cases (8.33%) only with NSCLC and below reference range in 12 cases (20%) – in 10 cases in patients with NSCLC and in two cases in patients with SCLC. In control group of 10 persons, serum level of OC was below reference range only in one case. Conclusion: The serum concentrations of osteocalcin were not correlated with findings performed bywhole-body bone scintigraphy in patients with lung cancer. Osteocalcin serum levels determination probably does not have diagnostic importance in lung cancer patients with suspected bone metastases.