The purpose of our study was to determine the emotional intelligence (EI), differential and general aptitudes and mathematics achievement of students in 6th year of primary education, analyze the possible relationship between these variables, the differences that may exist on mathematical achievement derived from EI and the aptitudes of students, and the value of the IE and aptitudes as predictors of mathematics achievement. A total of 34 students (13 girls and 21 boys), of 11.5 years average were involved in the study. Data collection was performed in 4 sessions of approximately one hour, one for each of the instruments used (TMMS, BADyG-E3, and qualifications lists). The results describe the student sample, their IE profile, aptitudes and average mathematics achievement, the relationship between EI and aptitudes in mathematics achievement, the influence of gender in the relationship and predictive value of the IE and aptitudes in mathematics achievement. We discussed our data for their significance in explaining the low performance in mathematics of Spanish students in international assessment tests as well as promoting factors of general academic success.