Despite its unfinished state, the Temple of the Holy Family, or Sagrada Familia, is Antoni Gaudi’s most widely recognized work and one of the most important milestones in the development of Catalan Modernism at the beginning of the twentieth century. This article aims to analyze the role played by concrete in the three different stages of the construction process and to illustrate the uniqueness of the Sagrada Familia. Reinforced concrete started being used in the building’s construction in 1918 to resist the tensions produced in the pinnacles of the facade. From that moment on, mass concrete, reinforced concrete, and prefabricated concrete have been used in response to the needs that have arisen. Lately, following in Gaudi’s innovative spirit, the latest advances in building technologies have been introduced in the Sagrada Familia . An example of this innovation is the use of high-strength concrete since 1998.