Cancer, the second primary cause of death for patients with serious mental illness (SMI) continues to be responsible for over 14 million new cases and approximately 8 million cases annually. Delays in diagnosis and unequal access to cancer care contribute to cancer mortality that is two to fourfold higher in people with SMI than in the general populace. Severe mental illness is an emotional, mental and behavioural disorder leading to a serious impairment and ultimately has major effect of life activities. Patients with the history of severe mental illness are at high risk of incurable cancer via a number of factors including overshadowing of diagnosis, low socioeconomic level and fragmented healthcare. Likewise, individual diagnosed and undergoing cancer therapy are prone to develop mental illness as an aftermath of chemotherapy. Averagely, patients with serious mental illness, for example bipolar disorder and schizophrenia, die 15-20 years earlier than the general populace, and thus widening the mortality gap. The primary causes of death for this population include cancer and cardiovascular disease, signifying that access to appropriate and timely precautionary services could help decrease untimely deaths. Also, severe mental illness can be effectively managed with increased access to mental-based treatment services to reduced related morbidity. Therefore, having a better understanding of subjects regarding early detection of cancer, mental health treatment/management and the association between these, could have a significant step in detecting possible causes of early mortality in patients with SMI.