Stepwise multiple regression analysis was used to ascertain whether basic concepts of mathematics(Basic concept) and prior knowledge of mathematics(Prior Knowledge) can make significant prediction on students' mathematics achievement(Mathematics Achievement). Stepwise variables selection method was used in order to get a parsimonious model which can explain most of the variance in the dependent variable by using least number of independent variables. Assumptions namely normality, homoscedasticity, linearity, and independence were met prior to multiple regression analysis. On the other hand, distance statistics(leverage measure and Cook distance) and influence statistics