This research examined the writing difficulties faced by Thai students taking the International English Language Testing System (IELTS) Academic Writing module. The study examined error patterns in IELTS Writing Tasks to highlight how English writing proficiency impacts international university admission prospects. Despite universities commonly requiring IELTS scores between 6.0 and 6.5, Thai test-takers have historically achieved mean scores of 5.5-5.7 in the writing section. Analysis of writing samples from 15 Thai candidates revealed prevalent challenges including time allocation, grammatical accuracy, organizational structure, and logical flow. The research sought to develop evidence-based recommendations for test preparation and inform pedagogical approaches, with the ultimate goal of helping Thai students improve their IELTS writing performance.