Prior studies have shown that students' achievement goals play a key role in their learning strategies, decision-making processes, and learning outcomes. However, a majority of these studies were conducted with undergraduate psychology students. Thus, there is a need to explore the role of students' achievement goals on their reflection behaviors and learning outcomes in different fields, including engineering education. Based on our literature review in engineering education, there are a limited number of studies that investigated the relationship between achievement goals and students' learning outcomes. Therefore, we conducted this exploratory research study to investigate the relationship between achievement goals, reflection behaviors, and learning outcomes of engineering students. We used the Achievement Goal Questionnaire-Revised (AGQ-R) scale to measure 69 sophomore engineering students' achievement goals. Six response variables were included: average reflection quality, the total number of reflections submitted, two exam scores, the final exam score, and the total weighted learning outcomes. Based on our analyses, we found that the mastery approach was significantly related to the total number of reflections, the final exam score, and the total weighted learning outcome variables. The performance approach was also significantly related to the final exam and total weighted learning outcome. Mastery avoidance was significantly related to the total number of reflections, the second exam, and the total weighted learning outcome. Finally, performance avoidance was significantly related to the second exam, final exam, and the total weighted learning outcome. Overall, our findings are informative to researchers in the engineering education field for better understanding students' learning strategies, reflection behaviors, and learning outcomes relating to their goal orientation. Thus, this study provides benefits to researchers and other stakeholders such as faculty members or administrators in engineering education to develop more effective intervention programs that positively impact student motivation and their learning strategies as well as learning outcomes.