This paper reports on a study that investigated the relationships among self-efficacy, task value, strategy use and performance in L2 writing. The participants were 304 undergraduate ESL (English as a second language) students in Malaysia. Questionnaires and writing performance tests were used to collect data. Writing performance was determined by a robust testing procedure which is usually employed in high-stakes writing tests. The results showed that four motivational constructs (self-efficacy, intrinsic value, attainment value and cost), and four writing strategy categories) meta cognitive, cognitive, effective and effort regulation) were significantly related to writing performance. The study also found that intrinsic value and self-efficacy contributed significantly to the prediction of writing performance after controlling for the other predictor variables of the study. Limitations of the study, directions for future research, and implications for writing instruction and language classroom were discussed.