Graphing calculators have become one of the most widely adopted technologies in mathematics education that have a powerful potential to help students master important mathematical concepts because they provide specific functionalities that are valuable for mathematics learning. The objective of this study is to compare the effect between the TI-Nspire CX graphing calculator (GC) strategy group and conventional instructional (CI) strategy group on students’ performance in learning Straight Lines and Statistics topics. This study employed the quasi-experimental nonequivalent control-group pretest posttest design. The samples of the study are two intact Form Four classes from four selected secondary schools in Perak and Selangor. For each school, one of the classes served as the experimental group (GC strategy group) while the other class served as the control group (CI strategy group). The total number of students in the sample is 96 in the control group and 111 in the experimental group.There are two instruments used in this study namely The Straight Lines and Statistics Achievement Tests to assess students’ performance on the Straight Lines and Statistics topics. Statistical inferences tests such as the independent t-test and ANCOVA were used to analyze the data. The results showed that students in the experimental group from all schools had significantly better scores in both tests than those from the control group. Integrating the use of TI-Nspire graphing calculators can be beneficial for students as this instructional strategy has proven to improve students’ performance. Furthermore, TI-Nspire has the potential to be a tool in promoting higher level mathematical thinking that encompasses mathematical problems solving, reasoning and mathematical exploration.