Tumors, especially malignant ones, are rare in children and adolescents, even though their number is increasing. When it comes to the liver, tumors can be benign and they include hemangiomas, hamartomas, and focal nodular hyperplasia (FNH). Malignant ones are far more deadly, and the most common ones are hepatoblastoma (HB) and hepatocellular carcinoma (HCC). Liver tumors take the third place in abdominal tumors in Pediatrics, right after adrenal neuroblastoma and Wilms tumor. A strong connection between liver tumors and environmental risk factors has not been found, but there are some indications that children whose parents have been in contact with metals which are usually used in welding, petroleum and paints have a higher chance of getting hepatoblastoma. Some researches also imply that children of smokers have hepatoblastoma more often than children of non-smokers. In clinical status of children with liver tumors, a palpable abdominal mass or distension is usually found. Some of the patients have anemia, thrombocytopenia, and leukocytosis due to the malfunction of the liver. In rare cases, if a child is suffering from both HB and HCC, the disease can manifest itself with anorexia, which causes weight loss, and high fever. Further diagnosis includes laboratory and imaging tests. CBC count, electrolyte levels, liver enzyme levels, liver synthetic function, and α -fetoprotein (AFP) levels are taken from the blood and to confirm the location as well as the density of the mass we resort to ultrasonography. If the consistency of the mass cannot be determined or the mass is solid, CT or MRI are indicated. They can define the precise location and number of changed areas of the liver and also detect any possible metastases which is useful for staging the disease. The images are suitable for choosing further treatment because they can give the proper information about the resectability of the tumor. Nevertheless, definitive diagnosis can be given after a biopsy has been performed and a tumor has been pathologically proven. The most important treatment of liver tumors is surgical resection. Since most tumors are massive or have already affected various parts of the liver, in over 60% of cases a primary resection can not be performed. Luckily, the tumor cells have a great response to systemic neoadjuvant chemotherapy. In patients that undergo chemotherapy, drop of serum AFP can indicate a positive response of the tumor cells and can lead to recovery. Unresectable liver tumors that do not respond to this kind of chemotherapy are an indication for complete hepatectomy and liver transplantation.