A portal-axle of bogies for light rail vehicles, such as for example trams or light rail metros with street running, is described, the light rail vehicles being characterized by a floor, i.e. a walking surface, lowered with respect to the rails. The portal-axle comprises two shoulders equipped with spindles for mounting wheels and with a central portion for structurally connecting the shoulders. Unlike conventional solutions, the central portion is not made by casting or forging, but advantageously is simply defined by at least two bars coupled thereto during the assembly. The bars are easily available on the market at low cost, have lower weight with respect to a traditional forged/cast component and allow modularity and versatility in dimensioning the portal-axle to be obtained.