OBJECTIVES: To investigate the expression of erythropoietin (Epo) and erythropoietin receptor (EpoR) on tumor cells of laryngeal carcinoma in in situ and invasive stage, and then compare the results with clinicopathological characteristics of tumor. PATIENTS AND METHODS: The study included 78 patients treated for squamous cell carcinoma of larynx in the period from 2003.-2009. The whole procedure took part at Department for Otorhinolaryngology and Head and Neck Surgery and at the Department of Radiotherapy and Oncology in Clinical Hospital Centre Rijeka. For the purpose of the study archive material from the Department of Pathology and Pathologic Anatomy as well as the data from medical history of the above mentioned Departments have been used. Immunohistochemical (IH) assay of Epo and EpoR expression was done on selected tissue samples of laryngeal squamous cancer cells. RESULTS: Malignant laryngeal cells express Epo and EpoR and are in slightly positive and significant correlation. IH analysis showed that the values of erythropoietin histoscore (Epo HS) and erythropoietin receptor histoscore (EpoR HS) do not differ according to gender of patients as well as to the diagnoses. Also, there is no correlation between these values and the age of patients, stage of cancer, histological tumor grade, proliferative index Ki-67, incidence or absence of disease recurrence and anemia. It is observed a statistically significant difference in the expression of Epo considering the outcome of treatment. Stronger expression of Epo is associated with longer survival. The expression of EpoR is not correlated with the treatment outcome. CONCLUSION: The research has proved the new role of Epo in malignant laryngeal cells due to the treatment outcome. Epo HS represents a significant predictor of treatment outcome. This finding offers new possibilities in planning of the patients’ treatment. Further on, since EpoR is not associated with any clinicopathological characteristics of tumor or with the treatment outcome the question of EpoR functionality in tissue of malignant laryngeal cells becomes imminent. Confirmation of our results in subsequent research could modify current treatment protocols and improve the treatment of patients with malignant neoplasms of larynx.