This paper focuses the development of Gaudi´s sources of inspiration starting from his earliest architectural works, such as the Casa Vinces, the Villa “El Capricho” and the Palau Güell Pavilion, in which the influence of the Mudéjar style is recognizable. Gaudí reinterprets the Mudéjar style according to his own taste, which resulted in the creation of elements characteristic of his architecture such as dynamic, playful roofs and domes, illogical and strange chimneys and richly decorated exteriors of buildings with broken ceramic tiles. With the development of his creative expression, Gaudí turned to the study of Gothic buildings from which he adopted the broken arches and created his own parabolic ones. The stainedglass windows, a key part of the decoration of the Gothic cathedrals, inspired Gaudí to richly decorate the interior. Gaudí complemented these innovative interpretations of historical styles with the use of iron, a modern industrial material from which he designed a variety of rounded and curved forms on the fences of portals, balconies and doors. Nature was the most important inspiration for him and in almost all his works there are elements inspired by wildlife. Gaudí´s artistic development and changes of his sources of inspiration are at the heart of this work and will be followed chronologically.