The multi-movement structures of Beethoven's instrumental works include some of the most obvious manifestations of his originality as a composer. His very first Viennese publications-the Piano Trios op. 1 and the Piano Sonatas op. 2-adopt the four-movement cycle that had previously been associated primarily with the symphony. And in his last five string quartets he transformed the conventional multi-movement cycles almost beyond recognition, particularly in the seven-movement Quartet op. 131, in which each movement runs directly into the next.This study investigates Beethoven's compositional approach to multi-movement structure, with the aim of gaining a better understanding of the underlying principles that influenced his musical decisions. Particular attention is given to an aspect of his sketching process that has received relatively little scholarly attention: multi-movement plans. These plans were generally sketched at an early stage in the compositional process, and outline preliminary ideas for the different movements of a work as a whole. Although Lewis Lockwood hypothesised that such plans were particularly frequent amongst Beethoven's sketches from 1800 to 1804, until now there has never been a detailed study of their role within Beethoven's sketching process throughout his career. This study reveals that multi-movement plans were a regular feature in sketches for instrumental works from 1800 onwards, and that they served a variety of purposes within the compositional process. Multi-movement plans from all stages of Beethoven's compositional career are transcribed and examined for what they can reveal about his conception of multi-movement structures.