There is substantial evidence that patients with schizophrenia have deficits in their ability to make inferences about others' mental states. However, the findings in schizotypy are mixed. In an effort to elucidate these mixed findings, the current study evaluated self-referential theory of mind (ToM) in positive schizotypy, or the ability to make inferences about others' mental states as they apply to the self. In addition, we differentiated between 2 ToM error types: hypermentalization (excessive mental state attribution) and undermentalization (overly simplistic or lack of mental state attribution). We used a 3-group design (positive schizotypy, negative affect psychiatric control group, and healthy control group) to assess ToM performance on the hinting task (Corcoran, Mercer, & Frith, 1995) and a newly developed self-referential version of the hinting task that differentiates between ToM error types. Results demonstrated that the schizotypy group made significantly greater self-referential hypermentalization errors than both control groups. Self-referential hypermentalization was significantly related to referential thinking, aberrant salience, interpersonal schizotypic traits, and functional outcome. (PsycINFO Database Record (c) 2019 APA, all rights reserved).