This paper presents one of five categories of findings of a qualitative study of students' experiences of challenges encountered in a web-based graduate program. The findings relate to the category of experiences with online asynchronous discussions. Data collection relied on a discussion, questionnaire and interview all conducted within WebCT™. The category's findings were grouped into four sub-categories of challenges as follows: student behaviour; text-only, online communication; purpose and quality of the discussion; and forum features. Challenges related to students' behaviour included domination of the discussion by individual students or groups of students resulting in feelings of exclusion, frustration and inadequacy. Text-only communication caused difficulties related to misinterpretation and conveying and deriving intent. Challenges related to the purpose and value of the discussion resulted from low quality and high quantities of postings to meet grade requirements. Technical features that presented challenges included the inability to delete messages.