This thesis is a study of the seven major symphonies of Serge Prokofiev. Each of the first seven chapters is devoted to one of the symphonies, and includes biographical information on the symphony, formal analysis and discussion of the individual movements, and the distinguishing characteristics of the work. Following each chapter is a diagram showing the form, themes, and key relationships of the individual movements. The final chapter is a short summary of the symphonies, noting both their individual differences and their many stylistic similarities.