The study determined the relationship between principals’ supervisory techniques and teachers job performance in secondary schools in Anambra State, Nigeria. Two research questions guided the study and two null hypotheses were tested at 0.05 level of significance. Correlation research design was adopted for the study. The population of the study comprised 5,286 teachers out of which 529 respondents were drawn using multi-stage sampling procedure. Two sets of researcher-developed instruments titled “Principals Supervisory Technique Questionnaire (PSTQ) and Teachers’ Job Performance Questionnaire (TJPQ) were utilized for data collection. The instruments were face validated by three experts and subjected to reliability test estimate using Cronbach alpha which yielded 0.77 and 0.74 for Clusters I and II of PSTQ respectively and 0.76 was obtained for TJPQ. Pearson’ Product Moment Co-efficient were used to answer the research questions, whereas the hypotheses were tested using t-test. The findings of the study indicated among others that there is a high positive relationship between principals’ classroom observation technique and teachers’ job performance in secondary schools in Anambra State. Based on the findings, it was recommended among others that Post Primary School Service Commission should organize training in supervision for principals to enable them up-date their knowledge and skills in applying classroom observation technique to improve teachers’ job performance.