The study investigated the efficacy of the students' perception of the influence of environmental characteristics on the academic performances of students in integrated science in Rivers State of Nigeria. Two hypotheses were formulated and tested in the course of the study. 600 junior secondary school 3 students (J.S.S. 3) were stratified and randomly selected from 300 junior secondary schools of the 359 junior secondary schools in Rivers State as at the time of the study. The sample was equally distributed among the male and female students. The student questionnaire and integrated science achievement test were used as data collecting instruments. The data collected was analyzed with the aid of the Z-test statistic and Pearson Product Moment correlation. It was found out that females performed better than their male counterparts and that environmental characteristic influenced their learning outcomes. It was then concluded that performance of students in integrated science is influenced by the environmental characteristics and recommended that stakeholders in education industry should meet constantly to discus issues concerning the teaching and learning environment of students particularly in integrated science at junior secondary school levels.