The purpose of this research work is to investigate the effect of class size in effective teaching and learning of junior secondary students in Ikpoba Okha Local Government Area of Edo State. In this project,. The researchers tried to look at the effect of class size in effective teaching and learning of Junior secondary schools students in Ikpoba Okha Local Government Area of Edo State. The methodology used was the questionnaire which was administered on the respondents, the questionnaire were completed and transferred into frequencies with the use of mean statistics. Some findings were out by the researcher and conclusion made. In the end some recommendations was drawn out which, include that there is need for government to expand the existing infrastructure in the school so as to accommodate the numbers of students admitted in the junior secondary school. Teachers should be employed as soon as more students are admitted so that teaching learning process will be effective. There is need for government to realize the essence of bringing up the policy of teacher students ratio such policies should be strictly adhered to the idea of admitting students without recourse to the facilities available in inimical to teaching and learning irrespective of the universal basic education (UBE) goals.