Purpose: This study aims to examine the writing outcomes of 6th-grade students learning English as a second language. Design/methodology/approach: In all 45 students in a text structure instruction (TSI) group were compared with 45 students in a self-regulated strategy instruction (SRSI) group and 43 students receiving traditional writing instruction. SRSI was adapted from the self-regulated strategy development (SRSD) model (MacArthur "et al.," 2015). The SRSD model includes self-regulation writing strategies, text and genre knowledge and think-aloud modeling. Findings allowed for a comparison of TSI and SRSI, in which organization knowledge does not need to be taught using SRSD methods. Measures of writing outcomes, including writing quality and summarization of main ideas, were administered after a one-month intervention. Findings: Results revealed that, compared with traditional instruction, the TSI and SRSI groups each exhibited better writing outcomes. Compared with the traditional instruction group, each technique had a unique impact: SRSI on writing quality, and TSI on main ideas included in written summaries. Linguistic and textual analyses of students' writing revealed that the TSI and SRSI group learners both demonstrated high syntactic complexity, content organization and lexical variation in their compositions. Research limitations/implications: The present study provides empirical evidence that explicit teaching of SRSI writing strategies or TSI can be implemented effectively and elicit gains in elementary school L2 learners' written output. A clear division does not exist between self-regulated writing strategies and text structure knowledge; the two techniques should be complementary, as suggested in the earlier SRSD model. Originality/value: Classroom-based research has addressed the need to enhance self-regulated capacity in writing. However, writing has become more challenging for primary school learners. In addition, writing is a cognitively demanding process. The plethora of processes involved in writing may be one of the factors that caused difficulties in writing. Thus, writing proficiency relies on the development of text structure knowledge and the fostering of self-regulation capabilities.