Horowitz received his rabbinic ordination at the Ponevezh Yeshiva in Bnei Brak and Beth Medrash Govoha in Lakewood, New Jersey.

In the late 1980s, he established a second synagogue in Har Nof, called Beis Shlomo, and continued as Senior Rabbi until 1995.

Horowitz frequently travels to Jewish communities in Israel, Europe, and North America to proselytize for Bostoner Hasidism.

Since becoming Bostoner Rebbe of Jerusalem in 2009, he has visited Waterbury, Connecticut,[6] Chicago,[7] Atlanta,[8] Dallas,[9] Denver,[10] and Budapest,[1] among others.

[11] In the Bostoner tradition, Horowitz has composed dozens of original songs and melodies[12] including "Borey Niv"[13] "Re'ay Nah"[14] and "Yivorechicho"[15]