Objective: leukocytosis as a paraneoplastic syndrome may occasionally occur in patients with lung carcinoma. The aim of the study was to assess the prevalence of leukocytosis in our sample of patients with lung carcinoma, to determine if leukocytosis is more common with a particular type of lung carcinoma, and whether leukocytosis caused inappropriate prescribing of antibiotics in patients with lung carcinoma. Methods: The study included 100 lung carcinoma patients treated at Department of Lung Diseases, General Hospital, during a three-year period (2003-2006). The methods of descriptive statistics were used on statistical analysis. Results: during a three-year period (2003-2006), 100 patients with lung carcinoma were treated at General Hospital, 23% of them with leukocytosis as a paraneoplastic phenomenon. Antibiotic therapy was prescribed in five of 23 (1,25%) patients. Conclusion: leukocytosis was most frequently associated with squamous cell carcinoma of the lung (43%), however, without statistical significance. Antibiotic therapy was prescribed in 1,25% of leukocytosis patients, suggesting that leukocytosis was correctly recognized as a araneoplastic phenomenon and was not unnecessarily treated with antibiotics.