The major purpose of this study was to assess principals’ use of power and to see if there is a significant relationship with teachers’ work motivation in government secondary schools of North Shoa Zone. To attain this objective descriptive survey research design with quantitative and qualitative approach was employed. From the total population of the study,1933 teachers and 56 principals in the 38 government secondary schools, by using simple random sampling technique 12 secondary schools were selected Accordingly, from the determined sample size 250 teachers (187 male and 63 female) teachers and 21 principals with their respective vices were included through systematic and comprehensive sampling technique respectively. Consequently, data were collected through standardized questionnaires and were analyzed using mean values, standard deviations, t-test and correlation. In addition to these, in-depth interviews were held with purposively selected 12 teachers and 6 principals. Similarly, data gained from the open ended items and interviews were analyzed concurrently using narration and direct quotation. From the analysis of the data, it was identified that principals dominantly employed positional power and use less power which was not effective to influence teachers. The interviews result also confirmed as most principals lack the concept and application of power effectively. Moreover, principals and teachers perception was not congruent on the use of power by principals. Most teachers preferred a principal who uses more personal power than positional power. In addition to these, the Pearson product moment correlation scores revealed, teachers’ work motivation had little positive relationships to legitimate, expert and reward power, whereas coercive and referent power bases had got little negative relationship to the aggregate men score of teachers’ work motivation. The results confirmed that principals’ use of power had demonstrated little contribution to enhance teachers’ work motivation. Finally, based on the findings, recommendations like: principals should be qualified, experienced and come to the position only with merit based competition and they should be trained before they assigned, principals should give emphasis to use more personal power … were forwarded. Moreover, future research should be considered in the form of case studies, since power is a dynamic process which changes in time and situation.