This study assessed the combined effects of students' achievement goal orientations (performance-approach goal and mastery-approach goal) and contextual factors (goal structures and task difficulty) on their performance. Researchers first asked 313 junior students about their achievement goal orientations and then randomly assigned them to one of four experimental conditions, all involving task difficulty × goal structure. A previously developed and validated maze task was used to manipulate task difficulty between low and high, and goal structure between performance and mastery. Performance was measured by the time students needed to complete the maze. Results showed three-way interaction between performance-approach goal orientation, task difficulty, and goal structure. Only students in the performance goal structure showed decreased performance (increased time to solve the maze) as task difficulty increased; the decrease was steeper when students had high performance-approach goal orientation. To understand fully their students' performance, educators should simultaneously pay closer attention to task difficulty, classroom goal structure, and students' goal orientations.