Heinrich Koller studied economics and social sciences at the Universities of St. Gallen, Paris and Winnipeg (1961-1966) and law at the University of Basel (1966-1970). For 3 years, he was a scientific assistant at the University of Basel, wrote his doctoral dissertation, and did the court and notary public practica in the Canton of Solothurn.
From 1987 to 1994, he was an associate lecturer, honorary lecturer and special lecturer for public law at the University of Basel. Beginning in 1992, he was also an associate professor for public law at the University of Basel. From 1978 to 1988 Koller was the legal counsel with Ciba-Geigy AG in Basel, primarily in the area of corporations and tax law, in particular mergers and acquisition. In 1988, he was named Director of the Federal Office of Justice of the Swiss Government. He was responsible for the preparation of the legislation process in all areas of law, the consultant of the federal council and the parliament, the supervisor of the lawmaking and the execution of the federal laws by the cantons and the representative of Switzerland in international organizations. He was the president of the Institute Board of the Swiss Institute for Comparative Law. He is a member of the foundation board of the Swiss National Fund for Supporting the Scientific Research and a founder member of the board of the Foundation of Continuing Education of Swiss Lawyers. Koller has written and edited a number of books, articles, reviews and held lectures. He focuses primarily on Swiss public law, European Union law and constitutional law. Koller completed service as a militia officer in the Swiss army with the rank of Colonel.
His major publications are: Die Umsetzung des EWR-Abkommens in das schweizerische Recht: Grundsätze und Methoden in: Accord EE/EWR-Abkommen, Kommentare und Erste Analyse (1992); Öffentliches Prozessrecht und Justizverfassungsrecht des Bundes (together with René Rhinow and Christina Kiss (1996).