The study was on ICT instructional-based variables and teaching effectiveness of teachers in selected public senior secondary schools in Cross River and Akwa Ibom States. To achieve this, two hypotheses were drawn from the stated research questions built around the dependent and independent variables.  Literature review was carried out according to the variables in the study. The survey design was used for the study. Two sets of questionnaires, Entitled; ‘Teacher Effectiveness Questionnaire’ (TEQ) and ‘ICT Evaluation Test Questionnaire’ (ICTETQ) were designed by the researchers to guide the study. Data was analysed using the Analysis of Variance (ANOVA) statistic. The hypotheses were tested at .05 levels of significance. The results of the findings were as follows: ICT resource availability has a significant influence on teachers’ effectiveness in public senior secondary schools in Cross River and Akwa Ibom States; ICT facilities accessibility have no significant influence on teachers’ effectiveness in public senior secondary schools in Cross River and Akwa Ibom States.  Based on the findings, it was recommended among other things that basic in service development, training and re-training on ICT be given to teachers and other basic infrastructures like hardware equipment and electricity be made available in these schools to enable teachers implement an ICT based teaching in schools and colleges