A major characteristic of contemporary TV series is their narratively complex scripts. These scripts include a number of elements such as long narrative arcs, multiple plots, temporal anachronisms and complex characters. Around the 1990s, American television consolidated narrative complexity, breaking away from traditional plot construction, combining these elements in an unconventional way. This dissertation aims to analyze the origin and development of the elements that make up the narrative complexity format. Through the analysis of the television series das séries This is us (2016-2021), Euphoria (2019-), I may destroy you (2020), Unorthodox (2020) and The crown (2016-), this research examines the constituent elements of complex narratives, as well as their applications in each television show. In this regard, the analyses rely on the works of Jason Mittell (2012), Silvio Anaz (2018), among other authors, focusing on the narratives that are woven throughout each series. It is concluded that narrative complexity incorporates elements that have been widely assimilated in cinema, television, theater, and literature, thereby originating a narrative format of its own.