The purpose of this study is to examine the structural relationships among self-efficacy, intrinsic value, test anxiety, instructional design, flow, and achievement among students at a Korean online university. To address research questions, the researchers administered online surveys to 963 college students at an online university in Korea enrolled in a Computer Application course. Structural equation modeling was conducted to investigate the structural relationships among the variables. Findings indicated that (1) self-efficacy and instructional design had statistically significant direct effects on flow, (2) self-efficacy, intrinsic value, and flow had statistically significant direct effects on achievement, and (3) flow mediates self-efficacy and achievement, and instructional design and achievement.