The current study aimed to investigate the relationship between the integrated writing tasks and strategy use in L2 learning depending on the different proficiency levels. Sixty university students were classified into two groups?the lower proficiency group and the higher proficiency group?based on their general English performance with 30 students for each group. For the study, the integrated reading-to-write task and the strategy inventory for integrated writing questionnaire were administered to gauge the learners’ writing outcomes and writing strategy use in general. The results revealed that there was a significant difference in the self-regulatory strategy use between the two groups. The findings also demonstrated writing test scores and test-wiseness strategy showed a positive correlation in the lower proficiency group while these two variables indicated a negative correlation in the higher proficiency group. Pedagogical implications were made based on the results.