This study investigates the writing strategies that Saudi university students utilise and the linguistic challenges they encounter during the process of writing in English. The study also compares the writing behaviour of two groups of writers: skilled vs. less skilled and male vs. female writers. Further, the possible inter-relationships between the main writing strategies and major linguistic challenges are explored. Data was collected using a writing proficiency test, think-aloud protocols (TAPs), observation, written compositions and stimulated recalls. The main sample consisted of 28 participants (14 skilled vs. 14 unskilled writers, 18 male vs. 10 female writers). Data analysis reveals that the writers frequently use ten writing strategies and encounter ten linguistic challenges. Some of the strategies are used more frequently by the skilled writers while others are more common among the unskilled ones. Similarly, male writers generally utilise fewer writing strategies than their female peers. While no significant differences are found between male and female writers in any one type of error, unskilled writers were found to make a larger number of errors in each category compared to the skilled writers. The study concludes with implications and recommendations for English writing pedagogy and research.