Professor Modugno took his law degree from La Sapienza University of Rome in 1961, with a thesis entitled La Teoria Kelseniana dell’Indistinzione dei Poteri [Kelsen’s Theory of the Indivisibility of Powers] (rapporteur Professor Massimo Severo Giannini, and co-rapporteur Professor Emilio Betti).

He was a pupil of Professors Vezio Crisafulli and Carlo Esposito in the field of Constitutional Law, and of Professors Emilio Betti, Angelo Ermanno Cammarata, and Ugo Spirito in the field of Philosophy of Law.

In 1967, he taught as a lecturer of Constitutional Law in the Department of Law at the University of Teramo.

From 1972 to 1975, he taught as a Professor of Constitutional Law in the Law Faculties of the Universities of Macerata (1972-1973) and Salerno (1973-1975).

In 1974 he served as Dean of the Law Faculty of the University of Salerno.

In 1975, as Full Professor, he taught Public Law Institutions in the Department of Political Science at La Sapienza University of Rome, and continued in that role until 1984.

From 1979-1980, he taught Italian and Comparative Constitutional Law in the Department of Political Science at Luiss University of Rome.

In 1984, he taught courses in Constitutional Law, Constitutional Justice, Theory of Interpretation, and Philosophy of Law in the Law Faculty of La Sapienza University of Rome. There he served as Director of the Institute for Theory of Interpretation.

Since 2011, he has been Professor Emeritus of Constitutional Law in the Law Faculty of La Sapienza University of Rome.

In addition to his courses at La Sapienza University of Rome, he has taught General Theory of Law, Methods of Law, Constitutional Justice, and Theories and Techniques of Lawmaking and Interpretation in the Faculty of Law at Luiss University of Rome, as well as Constitutional Procedure in the Department of Law of Roma Tre University.

Professor Modugno has served on the Editorial Boards of a number of academic journals, including Diritto e Società, Giurisprudenza Costituzionale, and Giurisprudenza Italiana. He is the director of several series of scholarly books, including the series published by the Italian and European Public Law Division of CRISPEL (the interdepartmental research center for political and constitutional studies and comparative law at the Roma Tre University), and the Costituzionalisti del XX Secolo [twentieth century constitutionalists] series, together with Marco Ruotolo. His principal fields of research, in which he has produced more than 300 academic lectures and published works (including books, essays, articles, and comments on judgments), include theory of law, sources of law, fundamental rights, and constitutional justice.