The kidneys are paired parenchymatous organs with a numerous number of functions essential for proper health management and normal body functioning. Their function can be impaired by many conditions such as kidney tumors. Kidney tumors can be generally classified as benign or malignant. Among malignant kidney tumors, renal cell carcinoma is the most frequent one. It has numerous histological subtypes with clear cell, papillary and chromophobe carcinoma being the most common ones. Risk factors for renal cell carcinoma development are smoking, hypertension and excessive body weight. Tumors usually occur sporadically, but they can have genetic background, as well. They are rarely symptomatic, and when the symptoms do manifest, it is usually when the disease is in its advanced phase. The triad of flank pain, haematuria and palpable abdominal mass is seen in nearly 10% of patients and their prognosis is more likely to be poor. Kidney tumors are rarely symptomatic and are usually accidentally discovered as a result of imaging methods indicated because of abdominal health concerns and not because of urinary symptoms. The diagnosis consists of history taking, physical examination, laboratory findings and imaging methods. Computed tomography is the gold standard in a kidney tumor diagnosis. The gold standard in the treatment of renal cell carcinoma is a partial or radical nephrectomy. Treatment depends on a type of tumor, its localisation, disease advancement, but on a patient's general health status, as well. That is why every patient requires an individual approach in order to obtain the adequate treatment.