The workshop on The Cosmology of Extra Dimensions and Varying Fundamental Constants, which was part of JENAM 2002, was held at the Physics Department of the University of Porto (FCUP) from the 3rd to the 5th of September 2002. It was regularly attended by about 110 participants, of which 65 were officially registered in the VFC workshop, while the others came from the rest of the JENAM workshops. There were also a few science correspondents from the national and international press. During the 3 days of the scientific programme, 8 Invited Reviews and 30 Oral Communications were presented. The speakers came from 11 different European countries, and also from Argentina, Australia, Canada, Japan and the U.S.A. There were also speakers from six Portuguese research institutions, and nine of the speak­ ers were Ph.D. students. The contributions are presented in these proceedings in chronological order. The workshop brought together string theorists, particle physicists, theoretical and observational cosmologists, relativists and observational astrophysicists. It was generally agreed that this inter-disciplinarity was the greatest strength of the work­ shop, since it provided people coming into this very recent topic from the various different backgrounds with an opportunity to understand each other's language and thereby gain a more solid understanding of the overall picture.