This research explores the relationship between cognitive writing strategies and students’ writing performance. The primary aim of this paper is to explore whether or not the two variables are interrelated. It also investigates how strong are the relationship between the two variables. The target observation was students at the moderate level. The sample was drawn systematically from population of 80 students at the English department Hasanuddin University 2008 - 2009 Academic year. The students were divided into 3 groups based on the results of their achievement test. The results indicated that 37 students included at the moderate level. Data were mainly obtained by means of achievement test where the students were asked to write about approximately 300 words in 60 minutes. The test was evaluated based on the five writing elements, assessed by two raters. Another way of obtaining data was through strategies questionnaire (10 Questions) and data were analyzed quantitatively using Kendall’s thau-c formula. Qualitative analysis was also applied. The results of the quantitative analysis through their achievement test are not significant (0.298). Its contribution is 11.4%. In contrast, in relation to questionnaire, the result shows that the correlation is significant (0.000) and its contribution is 70.3%.