There are several modernist buildings in the city of Valencia, Spain, built in the first decade of the 20th century, that reveal influences of the Viennese Jugendstil. This research work analyses those influences from the historical, architectural and theoretical point of view. It identifies which parallelisms and which connections in the period extended from 1898 to 1918 existed between the Valencian architectural modernist language and the Viennese Jugendstil architecture, and it points out the contribution that the understanding of the Viennese architecture brought into Valencias architectural modernist scene. This research study focuses its attention on the Modernism of Valencia. The built and planned architecture in Vienna between 1895 and 1914 is considered only as a reference to analyse Valencias Modernism. This work is not a compared study of the architecture of both cities. The way of studying the influences of the Viennese Jugendstil is divided into three different perspectives: The Historical Dimension, which studies the socio-cultural and historical context in which the Viennese Jugendstil and the Valencian Modernism were developed. Besides, it includes the research regarding the ways of introduction and influences of the Viennese Jugendstil into the architectural Modernism of Valencia. In order to purpose it, the more important artistic expositions at the beginning of the 20th century in Europe, the national and international architecture congresses, and the particular journeys to Vienna of several Spanish architects, who played most important roles in the transmission of the architectural language from Vienna to Valencia, are evaluated. A special attention is paid in this research study to the Spanish and foreign architecture publications, that were at disposal of the architecture students from Valencia, in the libraries of the Spanish architecture Universities (Madrid and Barcelona), where they studied, and also to the content of those publications. Moreover, the way in which those influences were received in Spain is analysed, and also, the architects from Valencia that reflected the influence of the Viennese architecture in their works are examined. Through published articles in Spanish architectural reviews and written texts and reports of some important Spanish architects in the architecture congresses, it is studied how the architectural movement around the group of artists who founded the Wiener Secession was understood in Spain. The second part of this research work, the Analytical Dimension, distinguishes the modernist projects and buildings in Valencia that present influences from the Viennese Jugendstil, and it classifies them according to the measure of assimilation of the Viennese influences and to the architectural innovation that they brought to the general Modernism in Valencia. The third part, the Theoretical Dimension, compares the theoretical speech of the Austrian architect Otto Wagner with the Valencian architect Demetrio Ribes; it reveals the existent parallelisms between them and the common way of understanding architecture of both. This research work is finished with the conclusions and discussions about the obtained results. It is completed with several attachments with some detailed lists of the projected and finished buildings in Vienna at the turn of the 19th century into the 20th, and the names and dates of the publications of those buildings.