Yitzchok Zilberstein (Hebrew: יצחק זילברשטיין, also spelled Silberstein) (born 1934) is a prominent Orthodox rabbi, posek (Jewish legal authority)[1] and expert in medical ethics.

In his teen years Zilberstein studied in the Slabodka yeshiva in Bnei Brak, where he became a student of Rabbi Yehezkel Abramsky, who gave him rabbinic ordination.

Zilberstein is an acknowledged halachic authority and is renowned as an expert in medical issues related to halacha, including organ transplant, abortion,[7][8] in vitro fertilization,[9] and multi-fetal pregnancy reduction.

[12] In 2009 Zilberstein was a member of a committee which investigated conversion and civil marriage in Israel and gave its recommendations to Rabbi Yosef Shalom Eliashiv prior to his rendering a psak (halachic decision) on the issue.

Aleinu L'shabayach (the title is taken from the Aleinu prayer at the end of the daily prayer service), compiled by Zilberstein's student, Rabbi Moshe Michael Tzoren, is based on the Zilberstein's private writings, shiurim and conversations; it includes a wealth of stories based on unusual she'eilos (questions) received by the Bnei Brak posek.