The purpose of this study was to investigate the impact of working conditions at school on teachers' level of instructional media use in the primary school system of Gedeo Zone, southern Ethiopia. The survey was made on a sample of 139 (24.4% female and male 75.6%) teachers who were randomly drawn from 9 primary schools (four rural and five urban primary schools). The instruments used to generate data were self-reported questionnaires tapping the level of instructional media use and the associated school-level environmental factors. The findings based on Factor Analysis revealed three independent dimensions of school environment factors related to the use of instructional media by teachers. It is further disclosed that the level of use of instructional media is low with an average frequency of use swinging between once in two weeks to twice in three weeks during four weeks of instruction. The implications of the findings related to pre-service and in-service teacher training are also discussed. (Contains 2 tables and 2 figures.)