We describe a pair of female monozygotic twins with Dercum's disease (DD) who presented simultaneously with unprovoked pulmonary emboli. Several genetic determinants have been associated with venous thromboembolism (VTE) but the overall influence of genetic factors is unknown. As yet there is no published evidence to support an increase in the risk of VTE in female monozygotic twins. DD is a rare condition characterized by multiple, painful lipomas. The underlying pathology of it is poorly understood. To date, there has been no recorded association with an increased risk of VTE but there have been reports of stroke-like events. It is unclear if these are caused by the condition itself or are co-incidental. We acknowledge the possibility of a coincidence but the two cases raise the question of an association between VTE and DD. This report should encourage further studies into the risk of VTE in female monozygotic twins and DD.