Tzvi was one of the prominent figures in his movement. He was a scholar and graduated from several universities. He was an active Zionist.
From 1937 to 1940 Tzvi was the head of the Keren Kayemet LeIsrael in Budapest. In 1939 he represented his movement in the Eretz-Israel Office. He worked with Ottó Komoly and Mihály Salomon. From 1943 he took part in the activities of the Relief and Rescue Committee and was the vice-president of the Hungarian Zionist Association. Tzvi also took part in the debates about the rescue of Jews held by Joel Brand and Israel Kasztner. He assisted in the selection of the passengers who left Hungary on 30.6.1944 on the Relief and Rescue Committee train. Tzvi was involved in the attempt to rescue Jews in Szeged by applying to the SS officer. As a result, part of the Jews who were taken to the Strasshof camp were from Szeged. Szilágyi himself left Hungary on the Relief and Rescue Committee train. After the war Tzvi returned to Hungary but did not take part in Zionist activities. He worked as a bookkeeper in one of the institutes of higher education and in 1958 he retired. In 1970 Tzvi intended to make aliya and a suitable apartment was even made ready for him in Kibbutz Ein Dor with the help of Arie Ya’ari. However, in the end he changed his mind.
