Introduction and aim Postoperative cognitive dysfunction is an important complication associated with increased morbidity, mortality, and reduced quality of life. Generally studies have focused on major surgery, while there is little evidence of the incidence of cognitive dysfunction in minor surgery. We aimed to compare general and spinal anesthesia in terms of cognitive decline in elderly patients after elective minor surgery using the Mini-mental state examination and Montreal cognitive assessment. Material and methods This observational study was conducted June 2014 to March 2015 at Ankara Numune Education and Research Hospital. The Mini-mental state examination and Montreal cognitive assessment scores were evaluated before and one day after the operation. Results The postoperative Mini-mental state examination scores of patients (26.23±2.77) were significantly lower than the preoperative scores (27.17±1.93) only in the general anesthesia group (p =0.003), while the postoperative Montreal cognitive assessment scores (22.87±3.88 for general and 23.13±4.08 for spinal anesthesia) were lower than the preoperative scores (24.32±3.19 for general and 24.35±2.84 for spinal anesthesia) in both the general and spinal anesthesia groups (p =0.000 and 0.019, respectively). The Postoperative cognitive dysfunction incidence was 32.9% using the Montreal cognitive assessment and was not significantly different between anesthesia methods. Conclusion Early Postoperative cognitive dysfunction is an important problem after elective minor surgeries, even with spinal anesthesia, in elderly patients. The Montreal cognitive assessment is an alternative tool that can be applied in a short time for screening cognitive functions in elderly patients. The cognitive screening of elderly patients perioperatively may be beneficial.