Introduction. The sense of agency over thoughts is the experience of oneself qua agent of mental action. Those suffering certain psychotic symptoms are thought to have a deficient sense of agency. Here I seek to explain this sense of agency in terms of metacognition. Method. I start with the proposal that the sense of agency is elicited by metacognitive monitoring representations that are used in the intentional inhibition of thoughts. I apply this model to verbal hallucinations and the like and examine the plausibility of this model explaining deficits associated with these symptoms. Results. By tying the sense of agency to metacognitive inhibition I propose that the loss of a sense of agency in certain psychotic symptoms is accompanied by a particular deficit in the patient's ability to control their own thinking. This is consistent with the experiences of those at high risk of developing hallucinations, who report more intrusive thoughts than controls. The model I present is able to explain why those at risk of developing verbal hallucinations and those suffering from verbal hallucinations have deficits in the intentional inhibition of thought. I defend this account from a possible objection by distinguishing the form of the intentional inhibition deficit displayed by those suffering verbal hallucination from that displayed by those suffering from orbital-frontal cortex lesions and posttraumatic stress disorder. Conclusion. A plausible hypothesis is that the sense of agency over thoughts is elicited by the metacognitive monitoring representation used to intentionally inhibit thoughts. The deficit in the sense of agency over thoughts associated with certain psychotic symptoms could be explained by a failure to properly metacognitively monitor certain thought processes.