Objectives: To investigate the relationship between the cell percentage of T regulator (Treg) cells of patients' specimens and disease severity, survivability, recurrence and metastasis in patients who were diagnosed with nasopharyngeal carcinoma (NPC). Design, Setting and Participants: Sixty patients who were diagnosed as NPC and treated by the same protocol were enrolled to the study. Patient files were reviewed retrospectively and their clinical and pathological results were recorded. Deparaffinized samples of nasopharyngeal carcinoma patients were stained immunohistochemically with anti-FoxP3 monoclonal antibody. All patients's Anti-FoxP3 stained slides were evaluated by the same pathologist. Stained Treg lymphocytes around the tumoral foci were investigated. Patients were divided into two groups according to the total anti-FoxP3-stained Treg cell counts of the specimens; that is, less than 20% of the total or more than 20% of the total. These groups were compared statistically. Main Outcome Measures: Intensity of FoxP3 which is related to negative tumor response was the main outcome measure. It was evaluated in terms of stage, survival, recurrence and metastasis. Results: The study group consisted of 42 male patients (70%) and 18 female patients (30%). The mean age was 47 14.9. NPC subtypes among the patients were undifferentiated non-keratinized type in 54 patients (90%), differentiated non-keratinized type in 4 patients (6.66%) and keratinized type squamous cell carcinoma (SCC) in 2 patients (3.33%). When the two groups were compared in terms of pathological subtype, there was no significant variation between the two groups. There was also no significant variation between the two groups when compared on the basis of tumor stage (P = 0.36 for T phase, P = 0.122 for N phase), early stage, late phase (P = 0.15), survival rate (P = 0.69 for general survival), recurrence (P = 0.2 for local recurrence, P = 0.37 for regional recurrence) and distant metastasis (P = 0.3). Conclusion: There was no significant relationship between the concentration of these cells in the stained specimens and the disease stage, survival rate, recurrence and distant metastasis discovered.