The purpose of this study was to examine the effects of algebraic equation solving intervention for sixth graders with mathematics learning difficulties (MD). A total of 48 students with MD were randomly assigned to either the algebraic equation solving intervention, "Mystery Math" (n = 24) or control condition (n = 24). The multicomponent intervention was based on the principles of explicit instruction and focused on improving conceptual and procedural knowledge of algebraic equation solving using concrete manipulatives. Students in the intervention group received instruction in pairs, 30 min per session, 3 sessions per week for 5 weeks (i.e., 15 sessions). The results indicated that the main effect of intervention was significant for 2 proximal measures of mathematics vocabulary, and conceptual and procedural understanding of algebraic equation solving with large effect sizes. However, the main effect of intervention was not significant for distal measures of comprehensive pre-algebra skills and whole-number computations. The findings demonstrate that grade-level standards can be successfully taught to students with MD. Implications for practice are discussed.