Tumor lysis syndrome (TLS) is a life-threatening oncologic complication caused by the lysis of a vast number of malignant cells resulting in metabolic derangements and organ dysfunction. TLS can occur spontaneously before initiation of any therapies often referred to as spontaneous tumor lysis syndrome (STLS), or shortly after the induction of chemotherapy, radiotherapy, or cytolytic antibody therapy. TLS is vastly seen in patients with hematological malignancies with high rapid cell turnover rates such as Burkitt lymphoma, acute myelogenous leukemia, and acute lymphocytic leukemia, and is rarely observed in solid tumors. However, TLS can occur in solid tumors, and there are multiple reports in the literature on the occurrence of TLS in various solid tumors. In this article, we report a case of STLS in small cell lung cancer followed by a brief review of the occurrence of TLS and STLS in small cell lung cancer.