This study aimed to investigate and analyze the neurobiological mechanisms affecting anxiety and depression in cancer patients in Urmia city and to determine the role of the main neurobiological indicators (cortisol, serotonin, dopamine, and hypothalamic-pituitary-adrenal axis function) during the period from October 1403 to April 1404. The research design was descriptive-analytical and the statistical population included all cancer patients referred to Urmia medical centers. Sampling was done using a stratified random method, and therefore 150 people were included in the study. Data collection tools included standard anxiety and depression questionnaires and neurobiological laboratory measurements (serum cortisol, serotonin, dopamine, and adrenocorticotropic hormone levels). The results showed that the average anxiety and depression scores were at a moderate to severe level. Cortisol and adrenocorticotropic hormone levels were higher than normal in most people, and serotonin levels were lower than the normal range. A significant correlation was observed between increased cortisol and adrenocorticotropic hormone with the severity of depression and anxiety (p<0.01), while decreased serotonin and dopamine were also associated with increased symptoms. Stepwise regression model showed that neurobiological variables predict a significant part of the variance in emotional symptoms of anxiety and depression. The findings indicate a significant role of neurobiological abnormalities in the severity and incidence of anxiety and depression in cancer patients.