The one-to-one computing environment provides students adaptive and individualized learning experiences, which has the great potential to enhance their learning performances, but it also requires students to actively motivate themselves to self-regulate their learning processes. This study examined the relationships between self-efficacy, task values, and self-regulated learning (SRL) in a one-to-one computing environment. Specifically, how task values (intrinsic value, utility value, and cost) mediate the relationship between students' self-efficacy and SRL was explored. A total of 299 seventh grade students (176 boys and 123 girls, with an average age of 15) from 8 classrooms of one public school volunteered to participate in this study. They were asked to complete a questionnaire pertaining to their perceptions of task values, self-efficacy, and SRL when using eSchoolbag, a type of one-to-one computing environment, to assist their learning. Results revealed that self-efficacy was a significant predictor of students' SRL, and their intrinsic value, utility value, and cost. Intrinsic value and utility value both significantly predict students' SRL. However, the cost of a task did not predict students' SRL. Utility value significantly mediated the relationship between self-efficacy and SRL, whereas the indirect effect of self-efficacy on SRL mediated by intrinsic value was not significant. The findings from this study provided important practical implications for the teaching and learning in one-to-one computing environment.