The past 10 years have seen substantial advances in molecularly targeted therapies for treatment of patients with cancer; however, chemotherapy will continue to be used. Therefore, the toxic effects of chemotherapy must be readily managed-especially nausea, vomiting, mucositis, and diarrhoea. For moderately to highly emetogenic chemotherapy, standard prophylactic treatment is an antagonist for 5-hydroxytryptamine 3 receptors (5-HT3R) combined with dexamethasone for the acute phase, and dexamethasone with another agent for prevention of the delayed phase. Palonoestron (a 5-HT3R antagonist) and aprepitant (an antagonist for the protachykinin 1 receptor) have been introduced for the prevention of emesis. Other agents such as cannabinoids, gabapentin, and olanzapine might also be effective. There is no standard prophylactic regimen for chemotherapy-induced mucositis. The most common treatment is optimum care of the mouth by use of mouthwashes. Keratinocyte growth factor, molgromastim, and transforming growth factor beta3 may also reduce chemotherapy-induced mucositis. Severe diarrhoea is another potentially fatal complication of chemotherapy and is most common in patients treated with irinotecan. Several interventions have been assessed for prevention and treatment of diarrhoea such as high-dose loperamide, non-absorbable antibiotics, budesonide, thalidomide, and fish oils, but only loperamide is used routinely. Symptom management has become a focus of clinical research, and development of personalised medicine should identify patients at increased risk of toxic effects because of molecular or biochemical factors, thus leading to changes in dose, early intervention, or use of alternative therapies.