Background: The therapeutic process is fraught with various feelings. This research focused on a specific type of negative feeling, namely self-doubt (SD). Aim: To explore and characterize the nature of SD among speech and language therapists (SLTs) (the frequency of SD, situations that trigger SD, emotions and thoughts related to SD, and coping strategies) in various stages of occupational experience. Methods & Procedures: A total of 267 SLTs answered an online survey. Respondents represented SLTs in all stages of vocational experience, with varying academic degrees, from a variety of employment settings. The survey addressed situations that trigger SD, thoughts, and emotions associated with SD and the background information of the respondents. Frequency distributions of the responses of the participants were determined, and independent-samples Kruskal-Wallis tests were conducted to examine if there were differences between groups that differed in their occupational experience on the frequency of SD, attitudes towards SD and emotions related to SD. Outcomes & Results: Differences were found between SLTs in various stages of professional development in several aspects of SD. Novice SLTs reported significantly higher levels of SD compared with experienced SLTs. In the face of SD, novice SLTs consider career abandonment significantly more than do experienced SLTs. They perceive themselves as a failure when experiencing SD to a significantly greater extent than do more experienced SLTs. In addition, SD is associated with various negative emotions. Conclusions & Implications: Self-doubt is a natural professional feeling. It may be harmful especially in the early stages of professional development. Our findings call for support and guidance in the face of SD.