Aim: Primary goal of this study was to establish the frequency and characteristics of postoperative cognitive dysfunction (POCD) in patients undergoing noncardiac surgery. Additional goal was to determine if age and comorbidities have an influence on the incidence of POCD before an operation, 7 days after an operation and 3 months after an operation. Materials and methods: 63 patients treated in Clinical Hospital Centre Rijeka have completed this prospective study. Montreal Cognitive Assessment Test (MoCA) was used to determine cognitive function before surgery, 7 days and 3 months after surgery. Patients younger than 18 and older than 75 were excluded from the study, as were those suffering from intellectual disability and dementia. Results: 25 (40%) patients had signs of cognitive dysfunction 7 days after surgery, which persisted in 8 patients (13%) 3 months after surgery. There was significant difference (p<0,0001) in the patients’ MoCA scores before surgery and 7 days after surgery. Significant difference (p<0,0001) was also found in patients’ MoCA scores 7 days and 3 months after surgery, while there was no difference (p=0,06) between the scores before surgery and 3 months after surgery nakon (p=0,1673). There was no statistically significant difference after splitting the patients into groups based on age and comorbidities. When analysing the MoCA test by subcategories, statistically significant difference between the mentioned time periods can be found in the following subcategories: executive functioning (p= 0,0008), attention (p=0,019), language and fluency (p<0,0001) and delayed remembering (p=0,017). Conclusion: Surgery led to the development of POCD in a significant number of patients, though most recovered in 3 months. POCD is a disease that deserves further study as it can have a significant impact on the quality of life and functioning in the postoperative period