After serving as rabbi in Ryczywół and Shinove, Shmelke was invited, in 1773, to become the rabbi of Nikolsburg in Moravia, where he made a powerful impact. On the first day of his being Rabbi of Nikolsburg, Abraham Trebitch a native of Nikolsburg reports him performing a miracle and bringing rain. It is told that his strong attachment to Chasidus angered many members of the community, which led to bitter quarrels that were quelled as a result of the personal intervention of Rabbi Elimelech of Lizhensk.