Maladaptive therapist schemas are hypothesized to generate difficulties within cognitive behavioural therapy (CBT) practice, training and supervision. Without adequate identification and management, they negatively affect the cognitions and emotions of the therapist, leading them to behave in ways that risk ruptures or therapy and supervision being delivered in a suboptimal fashion. Consequently, there is a need to synthesize the research that has been undertaken to date on the content, prevalence, identification and management of maladaptive therapist schemas. A scoping review was undertaken of studies that have been published since 2001 on the impact of maladaptive therapist schemas (also referred to interchangeably as beliefs or cognitions) in CBT practice, training and supervision. Thirteen studies were identified in a literature search from four electronic databases, a reference list search of identified articles and hand searches. Three overall themes were identified in the research: (1) prevalence of therapist schemas, (2) specific therapist beliefs and (3) therapist characteristics associated with the delivery of suboptimal CBT or supervision. While there is little empirical support for therapist schemas, therapist resistance and beliefs relating to the fear of using exposure therapy were identified. Therapist intolerance of uncertainty and self-esteem were recurrent factors. There is no consensus on how to define, identify, formulate or respond to maladaptive therapist beliefs or schemas in clinical practice, training or supervision. Further research is needed to better understand their origins, maintaining factors and appropriate management of their impact.