The National Cancer Institute Common Terminology Criteria for Adverse Events classification is the standard classification used by the physicians in oncology for reporting adverse events. This classification has evolved over the last years according to the emergence of new therapies. Reporting symptoms, quality of life (QoL) and toxicities via patient-reported outcomes (PROs) in clinical practice is not yet a standard of care, nevertheless many studies have been conducted recently to assess feasibility and impact of routine monitoring of PROs, which should enable for better management of toxicities and earlier detection of disease progression in a more patient-centered health care delivery system. The aim of this article was to discuss the advantages and limitations of both approaches, clinicians-reported outcomes and PROs. Growing evidence supports that the routine collection of PROs leads to improvement of QoL and overall survival of cancer patients.