BACKGROUND: Colorectal cancer (CRC) is the most common malignancy of the gastrointestinal tract and the third most common type of cancer worldwide. The COVID-19 pandemic, during the years 2020 and 2022, increased the difficulties in offering adequate early diagnosis and treatment to CRC patients worldwide. During this period, it was only possible to treat patients who evolved with complications, mainly intestinal obstruction and perforation. AIMS: To assess the impact of the COVID-19 pandemic on the treatment of patients with CRC. METHODS: A review of data from a total of 112 patients undergoing emergency surgical treatment due to complications of CRC was carried out. Of these, 78 patients underwent emergency surgery during the COVID-19 pandemic (2020/2021), and 34 were treated before the pandemic (2018/2019). Ethnic aspects, clinical symptoms, laboratory tests, histopathological variables, intra and postoperative complications, and 90-day postoperative follow-up were compared between the two groups. RESULTS: Between the years 2018 and 2019, 79.4% (27/34) of patients had intestinal obstruction, while 20.6% (7/34) had intestinal perforation. During the period of the COVID-19 pandemic (2020/2021), 1.3% (1/78) of patients underwent surgery due to gastrointestinal bleeding, 6.4% (5/78) due to intestinal perforation, and 92.3% (72/78) due to intestinal obstruction. No statistically significant differences were recorded between the two groups in ethnic aspects, laboratory tests, type of complications, number of lymph nodes resected, compromised lymph nodes, TNM staging, pre or intraoperative complications, length of stay, readmission, or mortality rate. When considering postoperative tumor staging, among patients operated on in 2018/2019, 44.1% were classified as stage III and 38.2% as stage IV, while during the pandemic period, 28.2% presented stage III and 51.3% stage IV, also without a statistically significant difference between the two periods. Patients operated on during the pandemic had higher rates of vascular, lymphatic and perineural invasion. CONCLUSIONS: The COVID-19 pandemic increased the rate of complications related to CRC when comparing patients treated before and during the pandemic. Furthermore, it had a negative impact on histopathological variables, causing worse oncological prognoses in patients undergoing emergency surgery.