Objectives: This study explored how illness perception and symptom severity might correlate with change expectancy (i.e., optimism about recovery) in anxiety patients in primary health care with a view to identifying guidelines for selecting interventions that may enhance anxiety change expectancy. Methods: This cross-sectional study examined potential associations between the expectancy of change in anxiety patients who sought psychological treatment at primary health care clinics in Singapore and their (a) illness perception (i.e., beliefs and emotional reactions regarding their own anxiety) and separately (b) symptom severity (i.e., intensity of their cognitive and somatic symptoms of anxiety). A total of 102 participants (mean age = 49.7, SD = 17.3, 64.7% female, 35.3% male) with mild to moderate symptoms of anxiety were administered the Anxiety Change Expectancy Scale (ACES), Illness Perception Questionnaire Mental Health (IPQ-MH), and State-Trait Inventory for Cognitive and Somatic Anxiety (STICSA). Results: Anxiety change expectancy was associated with both symptom severity and four specific dimensions of illness perception, i.e., chronicity, consequences, personal control (or self-confidence in being able to manage the anxiety condition), and emotional representation (or emotional responses to having the anxiety condition). Participants who had a greater optimism that their anxiety would improve were also more likely to believe that they had the ability to influence their anxiety symptoms. By contrast, the less optimistic participants reported more serious anxiety symptoms as well as more entrenched beliefs that their anxiety would involve a prolonged course, pernicious consequences, and substantial emotional distress. After controlling for demographic variables, a multiple regression model yielded personal control and emotional representation as strongest predictors of anxiety change expectancy. Conclusions: To engage anxiety patients in primary care treatment, it may be useful to emphasize interventions that promote patients' sense of self-determination and rapid reduction of anxiety.