Writing is a great challenge whether performed in the mother tongue or in a second or foreign language (L2/FL). Studies in L2 writing show that writing is a complex cognitive activity comprising a number of processes which includes the use of various strategies. This study aimed to examine strategies used in essay writing among 50 high-intermediate and low proficiency ESL upper secondary school students and to determine any significant differences in strategy use between the two groups. Data from the Writing Strategy Questionnaire indicate that the ESL students were moderate writing strategies users. The while-writing strategies were most frequently used whereas the revising strategies were least used. All students displayed approximately similar frequency use of strategies. They differed only in the type of strategies used. An implication of the study is that students need to be encouraged to use various strategies in improving their writing. Strategy training for ESL students is important to help them write successfully in the target language.