Introduction: Colorectal cancer has become the third cancer worldwide in terms of incidence and fourth in mortality. At diagnosis approximately 25% of patients will have liver metastases. With adequate treatment, the prognosis of stage IV patients reaches a survival of 40% at 5 years. We want to evaluate the response of the primary tumor of the colon from imaging and anatomopathological point of view in patients with colorectal cancer with liver metastases treated with chemotherapy and who then went to colon resection. Materials and Method: It is a retrospective and descriptive study of patients with stage IV colorectal cancer. The inclusion criteria were that they had cancer of the colon or upper rectum, with synchronous liver metastases, who have received at least 4 cycles of neoadjuvant chemotherapy and that subsequently went to resection of the primary tumor. Results: We recruited 9 patients, 4 men and 5 women. All received 4 or more cycles of chemotherapy prior to primary surgery. Of these, 8 had imaging control after chemotherapy. According to RECIST criteria, 3 patients presented complete response, 1 patient partial response and 4 stable disease. The anatomopathological study of the resected colon showed a macroscopic tumor disappearance in 2 patients, and microscopic in 1 patient. Conclusions: The complete pathological regression in our cases treated with neoadjuvant chemotherapy is a rare occurrence. This allows us to indicate the resection of the colorectal tumor site in all these cases.