Trace elements are minerals present in living tissues in small amounts. Some of them are known to be nutritionally essential, others may be essential, and the remainder are considered to be nonessential. Trace elements such as zinc, copper, selenium, iron, chromium and, others are essential elements for growth and body health. They form an integral part of many enzymes and bioactive centers that are responsible for biochemical reactions such as metabolism, protein and, DNA synthesis. They are said to contribute to the development of cancer based on epidemiologic evidence. The blood level of trace elements in the human body is affected by cancer and drug treatment. The low trace elements level is a sign of leukemia patients, where cancer cells consume body nutrients and essential elements for growth. The Libyan patients were divided into four age groups and were either newly or old diagnosed with leukemia, including patients with acute leukocyte leukemia, acute myeloid leukemia, chronic myelogenous leukemia, and aplastic anemia. The samples were tested for direct aspiration onto inductively coupled plasma spectrometry at specific wave lengths. The findings showed the blood level of trace elements in leukemia patients is lower than in the healthy individuals. A negative correlation between copper and zinc levels in leukemia patients was found. The copper level increases in leukemia patients as they get older.