his study focused on the use of Afan Oromo as a medium of instruction in Oromo Nation Zone of the Amhara National Regional state. The study was aimed at assessing and investigating practices and challenges of the use of Afan Oromo as a medium. of instruction. Five hundred and fifty two respondents were selected using a combination of cluster, random and comprehensive sampling techniques. The respondents were composed of five groups that is Primary school teachers, pupils, principals, cluster supervisors and Parents. Data were collected through questionnaires, interview and document analysis. To analyze the data, frequency tables, percentages, graphs and narrative descriptions were used. The findings indicated that the use of Afan Oromo as a MOI has made education responsive to the local and global needs. The use of mother tongue in education contributed to the academic success of students, to the increase in the enrolment of students of more disadvantage sects of the population especially in rural areas and made education play an active role in developing the Oromo people's language and culture. Leaming in ones mother tongue made it possible for the Oromo mass to exercise the globally recognized democratic rights of learning in own language. Teachers, ·pupils and parents who owned and used Afan Oromo as a medium of instruction for their relative children found to have positive attitude towards using Afan Oromo as a medium of instruction and positively assessed the use of Afan Oromo as a medium of in~truction. Challenges with the promotion of Afan Oromo as .., MOI are also found out that those parents in urban areas lacked initiation to teach their children in ~ mother tongue as a result of which enrolment to urban OMS has extremely declined. It is recommended that communicating and increasing mass awareness on the achievement gained is