This study aimed to investigate the effect of assistive technology for dyslexia on secondary school students’ performance and retention in Reading in Port Harcourt Metropolis, Rivers State by comparing it with collaborative and discussion instructional strategies. The study was guided by three research questions with corresponding hypotheses formulated in line with the objectives of the study. The design of the study was quasi-experimental and the population comprised two hundred and five (205) senior secondary school students one (S.S.1) in selected public secondary schools in Port Harcourt Metropolis. The sample size was two hundred and five (205) senior secondary school one (S.S.1) dyslexic students in Port Harcourt Metropolis, Rivers State. They were chosen through the census sampling technique. Experimental group 1 (N=60) was exposed to assistive technology, experimental group 2 (N=57) was exposed to collaborative instructional strategy and the control group (N=88) was taught through the discussion method. Data was collected through pre-test, post-tests and retention tests. Data were analyzed using Analysis of Covariance (ANCOVA). Findings showed that the performance of dyslexic students taught reading comprehension using assistive technology instructional strategy is higher than those of their counterparts taught using collaborative learning and discussion instructional strategies. Also, there was a significant difference in the effect of instructional strategy on the performance and retention of dyslexic students in reading and female dyslexic students taught Reading Comprehension performed slightly better than their male counterparts did. The study concluded that assistive technology instructional strategy requires students to participate in a collaborative setting, whereas collaborative learning and discussion require individuals to work together on self-directed tasks. Hence, it was recommended amongst others that government should provide assistive technology free of charge to dyslexic students to help them participate fully in the teaching and learning process, as well as influence their performance in Reading Comprehension.