Jordanian 8^th grade students revealed low achievement in mathematics through four periods (1999, 2003, 2007 & 2011) of Trends in International Mathematics and Science Study (TIMSS). This study aimed to determine whether spatial visualization mediates the affect of Mathematics Learning Strategies (MLS) factors namely mathematics attitude, mathematics motivation, mathematics self-regulation, mathematics self-efficacy, and mathematics anxiety on mathematics achievement. The study consists of 360 students from public middle schools in Alkoura district, selected through stratified random sampling. It employed 65 items to assess MLS, which consists, attitude (18 items), motivation (7 items), self-regulation (25 items), self-efficacy (5 items) and math anxiety (10 items). The mathematics test comprises of 30 items, which has eight items for numbers, 14 items for algebra and eight items for geometry while spatial visualization test consists of 32 items base on 2D and 3D views. The findings showed that spatial visualization fully mediated the relationship between motivation, math anxiety and mathematics achievement and it partially mediated the relationship between attitude and mathematics achievement. However, the results showed no mediating effect between self-regulation, self-efficacy and mathematics achievement. Considering these results, it is recommended that teachers should focus on mathematics attitude, mathematics motivation and math anxiety in classes to make achievement in mathematics easier. Moreover, these factors help students deeply understand mathematics through interest in spatial visualization as it mediates between relevant factors and mathematics achievement.