Preeclampsia is a major complication of pregnancy that can imperil the lives of both mother and baby; and it can cause lasting morbidity. The presence of diabetes during pregnancy incurs an increased risk of preeclampsia. This is especially true for pre-existing diabetes (type 1 and 2), both considered high risk factors for developing preeclampsia. Their presence alone is sufficient for the National institute for Health and Care Excellence (NICE guidelines, UK) to recommend aspirin prophylaxis. Excellent glycaemic control throughout pregnancy may plausibly reduce the preeclampsia risk. Inducing women with pre-existing diabetes will also likely reduce the overall risk. Aspirin remains the only medication option for preeclampsia prevention. There is high level evidence suggesting doses of 81 mg 150 mg can reduce the risk of preterm preeclampsia by around 62%, which is clinically significant. It is unable to prevent preeclampsia arising at term gestations - by far, the most prevalent type of the disease (and can cause significant morbidity). Furthermore, recent studies have shown aspirin may not be entirely benign – it incurs a bleeding risk such as postpartum haemorrhage. Calcium has been touted as being effective in reducing preeclampsia risk within regions of low calcium intake. However, a recent re-analysis of the Cochrane studies by another team has challenged the notion that calcium can prevent preeclampsia in any setting. Looking into the future, metformin, pravastatin and others are being avidly explored for their potential to prevent preeclampsia.