In the literature there are single case reports of mediastinal/chest and limb combined vascular malformations (previously labeled “hemangiolymphangiomas”). A variable outcome in such prenatally diagnosed cases is reported. Presented here is the only series of patients reported with these macrocystic, predominantly lymphatic malformations. Prenatal ultrasound scan and post-mortem examination findings are described. In our experience the outcome has been poor and this highlights the dilemma faced by clinicians and parents when these lesions are diagnosed prenatally. We present a series of five, prenatally diagnosed vascular (combined vascular malformations and simple localized lymphatic malformations) malformations. Three cases had lower leg involvement with extension into the abdomen and two cases had lymphatic malformations of the chest wall with involvement of the upper limb(s). Management of a twin pregnancy, in which one twin was affected, is described. In two cases, termination of pregnancy was undertaken because of the extensive nature of the lesion. One case died in utero and one in the neonatal period. The fifth case is an 11-year-old boy, whose lower limb deformity illustrates the considerable morbidity associated with this condition. © 2008 Wiley-Liss, Inc.