In this paper, we present an improved methodology to extract the small-signal electrical equivalent circuit of the parasitic elements using RF test structures for a 3D vertical nanowire transistor technology. The methodology is based on the extraction of the distributed parasitic elements from an open structure for which on-wafer S-parameter measurements were carried out up to 40 GHz. The electrical equivalent circuit of the passive device was then used for de-embedding of the transistor S-parameters for extraction of intrinsic small-signal parameters such as the gate capacitances.