This study investigated the relative effect of computer simulated instruction on Achievement of

students in Physics using type of school and gender as moderator variables. The simple random

sampling technique was used to select60 students from both private and public senior secondary

schools in Lagos Mainland Local Government Area and Ojo Local Government Area respectively.

The study adopted a pre-test post-test control group quasi- experimental research design. A

validated Physics Achievement Test (=0.78) was used in data collection. The study lasted for six

weeks. The data collected were analysed using one way ANOVA and t-test. The results showed a

significant effect of computer simulation instruction on students’ achievement in physics, a

significant main effect of school type and gender had no effect on performance varied on simulated

instruction on students "achievement in physics, a significant main effect of type of school on

students achievement in physics. The study established that computer simulation instruction

enhanced senior secondary school students in physics; performance varied on account of school

type; and gender had no effect on performance. The use of computer simulated instruction was

recommended for the teaching of physics so as to improve performance in physics at the senior

secondary school level.