Abstract: The purpose of the study was to observe and code the interaction patterns during physics lessons and to relate the identified patterns to students post-instructional attitude towards physics and achievement in low and high academic tasks. The sample consisted of 516 SS1students and 15 physics teachers drawn from 15 selected secondary schools in Calabar Education Zone of Cross River State, Nigeria. Each teacher/classroom was observed for 4 lesson periods spaced over a period of 8 week and the interaction patterns coded using the Science Interaction Categories. Two other instruments were used to collect data on students attitude and achievement in physics. The results of data analysis indicated, inter alia, that a significantly positive relationship exists between interaction pattern and students` post-instructional attitude and low academic task achievement.