Alberto Ginastera (1916-1983) was one of the leading South American composers of the twentieth century. Born in Argentina at a time when his country was striving to achieve a national identity and culture, Ginastera was recognized for combining the techniques of Western European art music with elements of Argentine folk music. His piano sonatas, composed during both his early and late periods, serve as excellent examples of this cultural synthesis throughout the course of his career. The Sonata No. 1 for Piano Op. 22 (1954), Sonata No. 2 for Piano Op. 53 (1981), and Sonata No. 3 for Piano Op. 54 (1982) have been analyzed and discussed in recent scholarship. Theorists have identified Western techniques such as sonata-rondo form, serialism, and symmetry in his compositions. Yet, when addressing rhythm, scholars have focused primarily on highlighting the Argentine dance or Amerindian rhythm that the music exemplifies and have neglected to apply Western analytical tools for analyzing rhythm. The goal of this paper is to approach rhythm and meter in the piano sonatas from a new perspective in order to identify Ginastera’s Western European musical techniques. Attention will be given to Ginastera’s use of and denial of metric hierarchy and periodicity. The paper will also focus on consonant and dissonant rhythms in the piano sonatas, as well as additive and subtractive rhythms. Because any discussion of rhythm and meter in Ginastera’s music cannot ignore its nationalistic origins, the paper provides an introductory chapter that discusses Argentine dance iii rhythms. However, the bulk of the paper aims to provide analyses from a Western art music viewpoint that illustrate Ginastera’s compositional manipulation of rhythm and meter.