Suicidal risk in mothers is a public health priority. The most commonly considered risk factors include biological, psychological, and psychosocial factors. Among biological factors, sleep disturbances are emerging as possible contributors incrementing suicidal risk during the peripartum period. Currently, only 12 studies examined the role of sleep in suicidal ideation and risk. Data showed that disturbed sleep and poor sleep quality increase the risk of suicidal ideation in pregnant and postpartum women with comorbid depression or psychiatric illnesses. These sleep disturbances have also been correlated with the risk of suicidal ideation during the peripartum period, independently, with an odd of more than twice. Insomnia symptoms and disorder are associated with increased odds of suicidal ideation in pregnant and postpartum women; they may be associated with high stress reactivity, hyperarousal, and rumination, which may favor depression, anxiety, and suicidal risk. Insomnia symptoms increase the odds of suicidal attempts during the postpartum period by more than three times. It is important to assess and treat sleep disturbances during the peripartum period in order to intervene on their negative consequences on peripartum psychopathology and suicidal risk.