Tanah Karo is one of the areas in North Sumatra with the majority of the population is Christian. Nonetheless, Muslims with minorities, have long entered and developed in Tanah Karo. One way of entering and developing Islam in this location is through dakwah which one of them pioneered by Al-Washliyah. This organization was born in Medan on 30th of November 1930, and active to sent of da’i to preach in Tanah Karo. To date, Al-Washliyah has contributed greatly to the spread of Islam in Tanah Karo. This is evident from the many da’i in Tanah Karo who are da’i-da’i from Al-Washliyah organization. This research will discuss further related about dakwah in Tanah Karo, with problem formulation: 1) How history of Al-Washliyah establishment ?, 2) How Da’wah by Al-Washliyah in Tanah Karo ?. The method used in this research is the method of historical research, with stages: heuristics, verification, interpretation, and historiography. Based on this research can be seen that Islamic dakwah movement in Tanah Karo, is a great gait of Al-Washliyah. Dakwah movement led by this organization is done by sending da’i Al-Washliyah to Tanah Karo, one of which is Ustadz H. Adnan Efendi. In its development, the da’wah efforts paid off with cheap Muslims in Tanah Karo in quantity and quality.