Achievement goal theory emphasizes the importance of achievement goals in learning behavior and performance, particularly in challenging tasks. However, little research has explored how achievement goals contribute to strategy use and integrated writing (IW) performance. The present study examined the relationship between achievement goals (task-, self-, and other-based), strategy use (planning, discourse synthesis, self-regulatory, and test-wiseness), and IW performance. This study involved 465 tenth-grade students from six schools in Hong Kong. Structural equation modeling results indicated that: (1) task-based goal positively influenced all four IW strategies, self-based goal contributed to self-regulatory strategy, and other-based goal had a positive effect on discourse synthesis and test-wiseness strategy; (2) planning and self-regulatory strategy positively influenced IW performance, whereas test-wiseness negatively predicted IW performance; and (3) the mediating effects of self-regulatory and test-wiseness strategy were confirmed. This study offers a nuanced understanding of the assessment of IW performance and the influence mechanisms between achievement goals, strategy use, and IW performance.