This volume presents the Proceedings of International Astronomical Union Symposium No.93 on Fundamental Problems in the Theory of Stellar Evolution. It contains the texts of all the invited papers, the abstracts of the contributed papers that were read by one of the attending author(s), and edited discussions. Only one abstract is included in this volume from each author who attended, and the abstracts of papers which were read on behalf of absent author(s) are not included. Those papers, which were read but are not included in the volume, are indicated by asterisks in the table of contents....