Klippel-Trenaunay syndrome (KTS) is an uncommon congenital condition, resulting in vascular malformations affecting capillary, venous, and lymphatic systems and bone and/or soft tissue hypertrophy. Magnetic Resonance Angiography (MRA) may be useful in assessing the severity of the disease and for treatment planning. We present two cases of two white men with the typical clinical presentation of Klippel-Trenaunay syndrome i.e. vascular malformations (capillary, venous and lymphatic) and localized bone and/or soft tissues hypertrophy. Splenic hemangiomas were evidenced in both patients and MRA was helpful in assessing and delineating the abnormal venous drainage system. KTS is a complex disorder whose true prevalence and etiology are still unknown. In most cases the emblematic clinical manifestation consisting in vascular malformations and extremity overgrowth is represented. KTS may be associated with several different conditions including scoliosis and splenic hemangiomas. The presence of the lateral marginal vein (LMV) is pathognomonic. Imaging is fundamental in confirming the diagnosis and for therapeutic strategies. An effective treatment does not exist to date and a multidisciplinary approach is usually required to prevent complications.  Kulcsszavak: Klippel-Trenaunay syndrome (KTS), Varicose veins, Magnetic Resonance Angiography (MRA), Lower limb hypertrophy, Port-wine stains, Lateral marginal vein (LMV)