Cancer disorders are the one of the leading causes of death in most developed and developing countries. They constitute a diverse group of pathologies in which abnormal metabolism and life cycle lead to the profound derangement's of host metabolism. With the recent advancement in the medical field, many cancer diseases are well controlled with early diagnosis and treatment. So, it is essential that clinicians must be aware the complications of cancer itself and its management. Tumour lysis syndrome (TLS) is an onco-metabolic emergency which occurs due to cancer cells targeted treatment (chemotherapy or radiotherapy) or from rapidly dividing cancer cells itself (spontaneous TLS). TLS was first described by Bedrna and Polcak in 1929 in a chronic leukemia patient treated with radiotherapy. It is characterized by a group of metabolic derangements characterised by hyperuricemia, hyperkalemia, hyperphosphatemia, hypocalcemia and uremia. The consequences are potentially lethal and may result in acute kidney failure, seizures, tetany and even sudden death. The scenario is further complicated in patient with underlying comorbid conditions and in patients at extremes of ages.