This study examined the influence of internal supervision on teachers’ effectiveness in public secondary schools in akwa ibom state, Nigeria. In order to achieve the purpose of this study two objectives were stated, two research questions were raise and two null hypotheses formulated to guide the study. The sub-variables of the study which were observation and records keeping and teachers’ effectiveness were reviewed, descriptive survey design was used, the sample size consisted of 400 respondents representing the population of 5777 drawn using Taro Yamene statistical tool and simple random sampling technique was adopted for selecting the respondents and the schools. Data were collected using a structured closed ended questionnaire entitled, Internal Supervision of Secondary Schools Questionnaire (ISOSSQ)” and “Secondary School Teachers Effectiveness Questionnaire (SSTEQ). The reliability of the instruments was established by using the data from trial testing procedure which yielded .83 for ISOSSQ and .87 for SSTEQ respectively, which showed that the instruments were reliable to be used in the study. Research questions and hypotheses were answered using t-test analyses at .05 level of significant. The findings of the study revealed that internal supervision methods such as informal observation and records keeping significantly influence teachers’ effectiveness in public secondary school in Akwa Ibom state, Nigeria. Based on the findings, it was recommended among others that Principals should always be proative in carrying out informal classroom observation, since it helps in encouraging teachers’ effectiveness and enhance the attainment of educational objectives. The findings of this study would contribute to knowledge in the sense that, researchers in different places and times would likely used as reference document conducted further studies on related issue.