Background. As society ages, the number of patients over 90 years old is increasing. Some of these patients need surgery. However, the treatment guidelines for elderly patients who need surgery remain unclear. This study aimed to assess short-term outcomes in patients ≥ 90 years old who under-went colorectal surgery. Materials and Methods. From November 2013 to May 2019, patients over 90 years old receiving colorectal surgery in Shuang-Ho Hospital were included in this study. Patients' characteristics, operative findings, and medical records were reviewed retrospectively. Primary outcomes measured 30-day mortality, morbidity, and length of hospital stay. We also compared surgical outcomes between elective surgery and emergent surgery. Results. Of the 46 patients, the mean age was 91.9 years, and the study included 25 male and 21 female patients. Of them, 18 patients (39%) under-went emergency surgery with three mortality. The most performed surgery is anterior resection (26%), and urinary tract infection (9%) and postoperative ileus (9%) were the most common postoperative complications. A total of 28 patients underwent elective surgery, and 14 had a laparoscopic operation. There was a statistical difference in operation time between laparoscopic and open surgery (p = 0.03) but no difference in blood loss, intensive care unit stay, and lengths of hospital stay. Conclusions. Although elderly patients are considered to have higher risks when having major abdominal surgery, our study showed a total mortality rate of 9%. For elective surgery, operative outcomes were similar between laparoscopic and open surgery. Further study is needed for detailed investigation.