The International Topical Conference on Effective Interactions and Operators in Nuclei, held at the University of Arizona in Tucson, Arizona, June 2-6, 1975, was the first international meeting on this subject. It brought together essentially all the principal physicists working in this field plus many other interested physicists. This volume contains the invited talks presented at the conference along with the discussions which followed each talk. There is also a list of participants and a copy of the conference program. This volume constitutes the second volume of the Proceedings of the Tucson Conference; the first volume, published by the University of Arizona, contained the abstracts of the contributed papers.