The current study aimed at investigating the contextual factors affecting university Saudi students' writing performance in different teaching/learning contexts, diagnosing writing difficulties from their own perceptions and reflections, ensuring real existence of  those difficulties, and then providing suggested practical solutions. The instruments of the study were (1) a questionnaire for identifying the writing difficulties related to cognitive, linguistic, situational, social, and psychological factors, and (2) a writing performance test for ensuring whether the writing difficulties are reflected in their real performance. Having applied the study instruments to two groups: six  Preparatory Year Students at AlBaha University (PYSBU) and six Language Center Saudi Students at Illinois University (LCSSIU), the data were collected and treated statistically. The results revealed that PYSBU exhibited writing difficulties/problems due to the lack of being exposed to the target language in its homeland, to the contrary of the  LCSSIU who feel at ease and perform well in writing classes. Also, there is a positive correlation between the study groups' perceptions about the contextual factors in writing classes and their writing performance. The study provided some practical recommendations and some suggestions for further research.