The current study intended to investigate the mediation role of mathematics motivation through the relationship between mathematics self-efficacy and mathematics achievement. The sample of the study consisted of 374 eighth-grade Omani students, 180 females and 194 males. PLS-SEM was used to investigate the direct effect between mathematics self-efficacy and mathematics achievement and indirect effect between mathematics self-efficacy and mathematics achievement through mathematics motivation as a mediation. This study showed that the mathematics motivation did not meditate the relationship between mathematics self-efficacy and mathematics achievement.