The study was carried out to find out some characteristics and causes of large class-size in public secondary schools in Port Harcourt, Rivers State. A sample of 1,332 respondents was drawn comprising 12 teachers and 1,320 JSS2 and JSS3 students. Two research questions guided the study. A questionnaire titled “Large Class-Size Characteristics and Causes Assessment Scale” (LCSCCAS), was used for data collection. The statistical tools used for data analysis were mean and standard deviation. Major findings were: Indiscipline, crowdedness, poor evaluation of students work, were major characteristics of large class-size while urbanization, free education, and handover of schools to missions, were the causes of large class-size in public secondary schools in Port Harcourt City LGA of Rivers State. To address this problem, it was suggested that government at all levels pay attention to the building of more classrooms, provide infrastructural facilities and adhere to the 1:40 teacher-students ratio as recommended by the National Policy on Education.
Keywords: Port Harcourt city, Public Secondary Schools, large class-size