This study investigated principals’ instructional supervision of teachers’ instructional strategies and assessment methods correlate of students’ academic performance in Business Studies in junior secondary schools in Taraba State. Two research questions and two hypotheses guided the study. The study adopted correlational survey research design using a questionnaire to collect its data. The population of this study consisted of 97 Business Studies teachers. As a result of the relative small size of the population (97), census sampling technique was adopted that allowed all the population to be used. A self-developed questionnaire titled “Principal’s Instructional Supervision of Business Studies Teachers’ Questionnaire (PISBSTQ)” was used for data collection. The instrument was validated by 3 experts from the department of Physical Sciences Education of Modibbo Adama University, Yola and trial tested using Cronbach Alpha to get a reliability co-efficient of 0.76. The data obtained were analysed using mean and standard deviation to answer the research questions; while Pearson’s Product Moment Correlation (PPMC) was used to test the hypotheses at 0.05 level of significance. The results of the study revealed that; there is a significant high positive relationship between principal’s supervision of teachers’ instructional strategies and students’ academic performance in business studies in junior secondary schools in Taraba state (r = 0.977, p < 0.05); and also that there was a significant high positive relationship between principal’s supervision of business studies teachers’ assessment method and students’ academic performance in junior secondary schools in Taraba State (r = 0.980, p < 0.05). The study concluded that principal’s instructional supervision of teachers’ instructional strategies and assessment method correlates of students’ academic performance in Business Studies. The study however recommended among others that respective stakeholders such as principals, school board, Nigerian Union of Teachers (NUT) should organise more often various professional development like seminars, symposium, workshops etc. for the improvement of business studies teachers’ instructional strategies. Keywords: Instructional Supervision; Instructional Strategies; Assessment Method; Academic Performance; Business Studies