Based on the 2007 Census conducted by the Central Statistical Agency of Ethiopia (CSA), this Zone has a total population of 1,389,800, of whom 702,580 are men and 687,220 women; with an area of 18,577.05 square kilometers, Guji has a population density of 74.81. While 129,852 or 14.31% are urban inhabitants, a further 5,315 or 0.38% are pastoralists. A total of 269,440 households were counted in this Zone, which results in an average of 5.16 persons to a household, and 258,540 housing units. The four largest ethnic groups reported in Guji were the Oromo (78.57%), the Gedeo (14.33%), the Amhara (2.59%) and the Somali (1.59%); all other ethnic groups made up 2.92% of the population. Oromiffa was spoken as a first language by 77.91%, 14.16% spoke Gedeogna, 4.31% spoke Amharic and 1.61% spoke Somali; the remaining 2.01% spoke all other primary languages reported. The majority of the inhabitants professed Protestantism, with 56.14% of the population having reported they practiced that belief, while 14.8% of the population were Muslim, 11.32% of the population said they held traditional beliefs, 7.49% professed Ethiopian Orthodox Christianity and 2.12% were Catholic.