OBJECTIVES: The aim of this study was to determine the association of depression with medullary carcinoma of the thyroid. EXAMINEES AND METHODS: The study was conducted at the Department of nuclear medicine and Department of endocrinology, University hospital Split. It included all patients who were hospitalized under the diagnosis of medullary thyroid carcinoma in a period of 14 years (2000 - 2014). Data were retrospectively collected from the medical history files, Beck depression inventory was verbally conducted among respondents, and all that was processed in Microsoft Office Excel 2007. RESULTS: In a period of 14 years (2000 - 2014) 38 of 41 patients were analyzed, of which 26 women and 12 men. Among them, there were 13 of those to whom the disease was detected between the ages of 40 and 50, 11 where the disease was detected between the ages of 50 and 60 years, 7 where the disease was detected between the ages of 60 and 70 years, and 3 patients whose disease discovered at the age less than 40 years. A larger number of patients was from suburban areas (n = 21) than the city (n = 17). By education a higher number of patients had secondary level of education (n = 24) than the level of a university degree (n = 14). The analysis found that 10 of the respondents male and 22 female patients had elevated calcitonin preoperatively. After surgery, 24 of the total number of patients had elevated calcitonin postoperatively. After completing the questionnaire Beck Depression Inventory was found that the largest number of minimally depressed patients (n = 22), followed by moderately depressed (n = 6), the harder depressed (n = 6) and slightly depressed (n = 4). There was a statistically significant difference in the responses to the questionnaire with respect to age detection of disease (p = 0.0001), and the difference between the responses of those whose disease was diagnosed before and those who have been diagnosed with the disease after 51 years of age (p = 0.0066). CONCLUSION: Medullary thyroid cancer occurs more often in women, and between the ages of 40 and 50 years. This research has not been proven correlation depression and medullary thyroid cancer, since the majority of patients minimally depressed.