This study investigated the effect of assistive technology and peer tutoring on mathematics achievement of academically gifted secondary school students with dyscalculia in Ibarapa Division of Oyo State, Nigeria. Three hypotheses guided the study. A Pretest-posttest quasi-experimental research design was used for this study. The study sample consisted of 178 academically gifted students with dyscalculia selected using a proportionate stratified sampling technique. They were grouped into two experimental groups and a control group. The three groups were pretested using the Mathematics Achievement Test (MAT) designed by the researchers (r = .78). Treatment packages were administered to the experimental groups while the control group was not administered any treatment. Data collected were analysed using descriptive statistics and analysis of covariance (ANCOVA). Ethical considerations were adhered to. Results show significant main effect of gender [F(1, 176) = 19.336; p-value = .000 < .05)] on mathematics achievement of the participants and significant main effect of the treatment [F(2, 175) = 464.770; p-value = .000 < .05)]. No significant interaction effect of gender and the treatment [F(2, 175) = .050; p-value = .824 < .05)] was found. Investment in a variety of assistive technology designed to support students with dyscalculia and the establishment of peer tutoring programmes within the school was recommended.