Among his friends from this period were Avgust Žigon, who later became a renowned literary scholar, the Slovene writer Ivan Pregelj and the Friulian prelate Luigi Fogar, who later served as bishop of Trieste.

Among his friends from the period were Andrej Gabršček, the leader of the National Progressive Party in Gorizia and Gradisca, the young historian and jurist Bogumil Vošnjak and the lawyers Dinko Puc and Drago Marušič, who all later became prominent liberal politicians in the Kingdom of Yugoslavia.

The court was located in Zagreb and during his stay in the Croatian capital, Gradnik enjoyed the company of Croat intellectuals like the writer Vladimir Nazor, historian Antun Barac, and poet Ivan Goran Kovačić.

After September 1947, when the Slovenian Littoral was annexed to Yugoslavia, he regularly visited his native village, spending most of the summer season writing poetry.

Gradnik's early poetry was strongly inspired by both the older generations of Slovenian poets (the modernists, but also Simon Gregorčič and France Prešeren) and the European decadent movement.

One of the specific traits of Gradnik's early period was his intense focus on the relationship between Eros and Thanatos: that is, between erotic passion and the motive of death.

He later moved away from decadentism, rediscovering his Roman Catholic faith and turning to more mystical themes, maintaining a simple and plain language.

He also translated works of other important authors, including Francesco Petrarca, Giacomo Leopardi, Rabindranath Tagore, Giosuè Carducci, Romain Rolland, Omar Khayyam, Jovan Jovanović Zmaj, Vuk Karadžić, Ivan Mažuranić, Petar Petrović Njegoš, Ugo Foscolo, Anton Chekhov, Juan Ramón Jiménez, John Erskine, Federico García Lorca, Sándor Petőfi, Endre Ady.

His membership in the High Tribunal for the Security of the State, which condemned several Communist activists, was a further reason for his fall into disgrace during Josip Broz Tito's regime.

Nevertheless, many of his poems gained much popularity in his home region and a local school in the Italian commune of San Floriano del Collio was named after him in the late 1970s.

He became a major source of influence for the younger generations of postmodern authors, such as Brane Senegačnik, Nevin Birsa, Aleš Šteger, and others.

Since mid-1996, an annual festival has been held in August in his home village of Medana, called Days of Poetry and Wine (Dnevi poezije in vina), to which young international poets are invited.