The main purpose of this study was to investigate the opportunities that have promoted the use of Hadiyyisa as a medium of instruction, the challenges thet were faced in due course of its implementation and the successes that have been gained as a result of the implementation of Hadiyyisa in the primary shools of Hadiyya Zone for instructional purpose. To this end, a descriptive survy method was employed to collect and analyze data. Mainly, concurrent nested approach was followed during the collection and analysise of data. Accordingly, sampling was carried out through both random and purposive sampling techniques. Thus, nine sampled schools were selected from Soro, Misha and Misrak-Badawacho woredas of Hadiyya Zone. The subjects of this study were 30 teachers, 170 students, 10 educational officials and 16 parents. Data were gathered through quetionnaires, interview and observation. The research result indicates that relatively stimulated community attitude and psychological readiness to use mother tongue, Enthsiastic feelings of Hadiyya intellectuals, positive support of local Political Authorities, experience gainedfrom the Literacy Campaign and National Language Policy as some of the opportunities that have induced the use of Hadiyyisafor instructional purposes. On the other hand, scarce instructional materials, insufficiently simplified translation of teaching materials, insuffiCient training to develop skills of instructional language and insuffiCient participation of teachers in preparation and evaluation of the instructional materials were some of the challenges that were identified by the study. Moreover, this study also had identified successes in that relatively increased students enrollement, decreased dropouts and repetions rates as were successes. Besides this, research result also indicated those most likely improved students' selj-estt~m and selj-expression, motivated classroom activities, preparation of subject dictionary in the vernacular language and giving education supported by radio transimition in Hadiyyisa and some others as successes gained because of the use of Hadiyyisffor instructional purposes though researcher believes that many other factors would also contribute to this result