Mathematics is one of the important disciplines for students to solve day-to-day problems in life. Attitude towards mathematics and mathematics learning is critical for a better learning to happen. This study was conducted to investigate the effect of instructional approaches on attitudes of students towards mathematics learning. Quasi-experiment research was conducted in middle schools at Addis Ababa City Administration, Ethiopia to investigate the use of visualization techniques (VT), problem-based learning approach (PBLA), visualization techniques-assisted problem-based learning (VT-PBLA), and conventional instructional approach (CIA) as instructional approaches and their effect on students' attitude towards learning Mathematics. Four intact classes were selected of which the three were used as intervention groups named intervention group 1 (IG1), intervention group 2 (IG2) and intervention group 3 (IG3) each of which took specific instructional approach as an intervention and a comparison group (CG) that were assigned using simple random sampling techniques. The sample size used were 48, 49, 48, and 47 students, respectively. Both pre and post-attitude Likert scale items were prepared and administered to the respondents before and after the intervention respectively. Paired samples t-test and ANCOVA were employed for analysis, and the results of the study show that the group taught with VT shown statistically significant difference on attitude and on each of the components of attitude, except for engagement. Moreover, the group taught with VT-PBLA also shown to have a statistically significant difference on attitude and their components except for engagement and confidence. PBLA alone did not show any significant mean difference in students' attitude towards learning mathematics and each of the components. The post-intervention comparison also showed significant mean difference between the groups for the overall attitude and the components of attitude except for engagement and confidence. These deviant findings seek further investigation to identify the possible causes or any possible amendments that could account to the instructional approaches.