Sunitinib, a multi-targeted receptor tyrosine kinase inhibitor, has demonstrated survival benefit in patients with metastatic renal cell carcinoma (mRCC) and is generally well tolerated with most adverse events, manifesting as mild to moderate in severity. The most frequent related adverse events include hand-foot syndrome (HFS), hypertension, proteinuria, cardiac toxicities, myelosuppression, fatigue/asthenia, hypothyroidism, diarrhea and hepatotoxicity. The study aims to determine incidence of adverse events among patients with metastatic renal cell carcinoma (mRCC) treated Sunitinib within five years from 2010 to 2015 and comparing the results with data from literature. The study included a total of 56 patients treated with Sunitinib, with a dose of 50 mg (Schedule 4/2). Due to adverse events and individual safety and tolerability, at the indication of the personal clinician, 11 patients needed dose reduction, with a continuous dose of 37.5 mg, daily and 28 patients continued the dose of 50 mg taken daily, on a different schedule (2/ 1 schedule). The most important toxicities were anemia, leukopenia, thrombocytopenia, gastrointestinal effects (diarrhea), fatigue and hypertension. After dose reduction or modified schedule the incidence of the most frequent toxicities (HFS, leukopenia, thrombocytopenia and fatigue) decreased, but hypertension was still observed in 30% of patients. The results are similar with data from literature. Early identification of individuals at risk and monitoring patients during Sunitinib treatment is very important and it can facilitate early intervention with prophylactic measures or supportive treatment, thus increasing quality of life and adherence to treatment. Further studies need to establish which targeted population can benefit the most from adjusted regimens and to correlate them with prognostic factors for survival.