Premature ovarian insufficiency (POI) involves loss of ovarian function before age 40. POI has been associated with neurological dysfunction and an increased risk of dementia, perhaps due to depletion in estrogen levels. The present review discusses the effects of POI caused by genetic disorder, natural premature menopause, surgical menopause, breast cancer treatment and gonadotropin-releasing hormone (GnRH) agonist treatment. Overall, data suggest an increased risk of neurological disorder where POI is due to premature menopause or induced from surgery. This increased risk appears to be most apparent on domains of global cognitive and verbal memory tests. Where POI is caused by genetic disorder, observed cognitive deficiencies may be more likely to have a genetic basis rather than being due to the effects of sex steroids on the brain. Findings related to loss of cognitive function after chemotherapy or GnRH treatments are mixed. There are also discrepant data related to use of hormone therapy after POI (particularly after surgical menopause). After surgery, hormone treatment appears to be most beneficial if initiated close to the average natural age of menopause.