This study was carried out to find out the relationship that exists between parental involvement, Mathematics self-efficacy and Mathematics achievement motivation of elementary school students in Nigeria. The participants were one hundred and seventy-five girls (175) and one hundred and sixty-eight boys (168) selected from five public and five private elementary schools in Lagos, Nigeria. The instrument titled Mathematics Achievement Motivation of Elementary School Students in Nigeria Questionnaire measured the students self-report response to items on parental involvement, Mathematics self-efficacy and Mathematics Achievement motivation. Pearson Product Moment Correlation analysis was used to test the formulated hypotheses. The result revealed a significant positive correlation between general parental involvement and Mathematics achievement motivation, Mathematics parental involvement and Mathematics achievement motivation, Mathematics self-efficacy and Mathematics achievement motivation, parental involvement and Mathematics self-efficacy and between cultural orientation and Mathematics achievement motivation.