During the last decade, increasing attention has been paid to the role of learner in the process of language learning and testing. Moreover, there is a general consensus in the literature that motivation is one of the key learner characteristics. The objective of this study was to explore the role of journal writing as a self-assessment technique in promoting Iranian EFL learners' motivation. The participants were 60 intermediate students in two groups. The particular self-assessment technique used in the experimental group was journal writing. At the beginning and end of the semester, both groups took a language proficiency test to ensure their homogeneity, and completed a questionnaires regarding motivation. The results revealed that writing journals in a regular base had a role in promoting the learners' motivation.