Medebay Zana is one of the woredas in the Tigray Region of Ethiopia. Part of the Semien Mi'irabawi Zone, Medebay Zana is bordered on the south by the Tekezé River which separates Tahtay Adiyabo from Tselemti, on the southwest by Asigede Tsimbela, on the northwest by Tahtay Koraro, on the north by La'ilay Adiyabo, and on the east by the Mehakelegnaw (Central) Zone. The administrative center of this woreda is Seleh Leha; other towns in Medebay Zana include Debre Kerbe.
Based on the 2007 national census conducted by the Central Statistical Agency of Ethiopia (CSA), this woreda has a total population of 125,028, an increase of 97,237 over the 1994 census, of whom 61,977 are men and 63,051 women; 10,526 or 8.42% are urban inhabitants. With an area of 2,685.12 square kilometers, Medebay Zana has a population density of 46.56 people per square kilometer, which is greater than the Zone average of 40.21. A total of 27,689 households were counted in this woreda, resulting in an average of 4.52 persons to a household, and 26,918 housing units. The majority of the inhabitants said they practiced Ethiopian Orthodox Christianity, with 98.24% reporting that as their religion, while 1.74% of the population were Muslim.
The 1994 national census reported a total population for this woreda of 97,237, of whom 47,973 were men and 49,264 were women; 6,304 or 6.48% of its population were urban dwellers. The largest ethnic group reported in Medebay Zena was the Tigrayan (99.89%), and Tigrinya was spoken as a first language by 99.93%. The majority of the inhabitants practiced Ethiopian Orthodox Christianity, with 97.82% reporting that as their religion, while 1.89% were Muslim. Concerning education, 10.15% of the population were considered literate, which is greater than the Zone average of 9.01%; 10.34% of the children aged 7-12 were in primary school, which is less than the Zone average of 11.34%; 0.31% of the children aged 13-14 were in junior secondary school, which is also less than the Zone average of 0.65%; and 0.08% of the children aged 15-18 were in senior secondary school, which is less than the Zone average of 0.51%. Concerning sanitary conditions, about 49% of the urban houses and 9% of all houses had access to safe drinking water at the time of the census; about 11% of the urban and 4% of all houses had toilet facilities.