Health-related quality is of life of great importance in cancer care. This prospective study aimed to evaluate the impact of chemotherapy and bevacizumab on the activities of daily living, cancer symptoms, and general well-being in 59 metastatic colorectal cancer patients. We gathered information using the EORTC QLQ-C30 and QLQ-CR29 questionnaires. The paired sample t-test, MANOVA test, and Pearson’s correlation test were used to analyze the presence of significant differences in mean scores before and after 6 months of treatment. The results revealed significant differences in the functioning and symptoms that influence patients’ quality of life after 6 months of treatment: increased pain (p = 0.003), nausea and vomiting (p = 0.003), diarrhea (p = 0.021) and decreased appetite (p = 0.003). At the same time, there were several aspects that improved the quality of life. Increases in emotional function (p = 0.009), cognitive function (p = 0.033), and perception of body image (p = 0.026) were observed after 6 months of treatment. Elderly patients reported a higher frequency of stools (p = 0.028), and young patients had increased concerns about body perception (p = 0.047). Assessing the quality of life of metastatic colorectal cancer patients is an important way to identify and treat symptoms related to both cancer and therapy by establishing a holistic care plan and implementing measures to increase the quality of life.