Together with his "maestro" Vittorio Emanuele Orlando, Romano is widely regarded as the leading exponent of the Italian school of public law of his time.

Though he maintained an uncommitted public profile during the Mussolini government, Romano was a member of the scientific committee on the antisemitic law journal Il diritto razzista.

In 1909, Romano moved to the University of Pisa as professor of administrative law, where he delivered his inaugural lecture "The Modern State and its Crises".

[6] In October 1928, Romano joined the National Fascist Party and in the same year was appointed as President of the Consiglio di Stato (Council of State), the Italian administrative high court.

[6] He spent the last years of his life in solitude working on his book Frammenti di un dizionario giuridico ("Fragments of a Legal Dictionary"), and died in Rome on the 3 November 1947.

[citation needed] Among his disciples are Guido Zanobini, Giovanni Miele, Massimo Severo Giannini and Paolo Biscaretti di Ruffia.

[10][11] Romano joined the National Fascist Party in October 1928 and, in the same year, he was appointed as President of the Consiglio di Stato, Italy's highest administrative court.

[12] Scholars also disagree on whether his adherence to Fascism should be understood as technical collaboration, which had the merit of counteracting the regime's most-radical tendencies,[13] or whether it has the significance of a truly committed choice.

[20] Alongside the state and the international community, Romano focussed on the proliferation of self-regulating legal orders, which he called "unequivocal signs of a social pluralism typical of the dynamic society of the early 20th century".

[11] As was his French contemporary Maurice Hauriou, Romano was concerned with the development of organised societal structures such as mass political parties and trade unions, whose normativity depends on their independent capacity to obtain allegiance rather than on state recognition.

Romano urged jurists to avoid "any contamination of the 'juristic point of view' with non‐legal concepts and methods" and "availed himself of the tools of legal dogmatics".

[3] Shortly after the Nazis came to power, Carl Schmitt, a prominent German public lawyer and critic of legal positivism, embraced Romano's institutionalist theory, as he acknowledged in his essay On the Three Types of Juristic Thought (1934).

Unlike Romano, who viewed society as comprising multiple, sometimes competing legal orders, Schmitt conceived of this plurality as subordinate to the state.