This online analogue study examined psychologists' current mental health diagnoses disclosure practices to children. Specifically, this dissertation investigated participants' self reported likelihood to disclose mental health diagnoses in relation to both psychologist (i.e., clinical services provided and years of clinical service) and client (culture, age, cognitive ability) characteristics. Forty-seven certified American Board of Professional Psychology (ABPP) Psychologists were recruited via email listserv for this research. Participants rated their likelihood to disclose mental health diagnoses to vignettes depicting children with varying demographic characteristics: culture, age, and cognitive ability. Participants also responded to open-ended questions exploring their current mental health diagnosis disclosure practices, including the impact of specific diagnoses on disclosure. Analyses of open-ended questions revealed that psychologists consider the following factors in their decision to disclose diagnoses: (1) child characteristics (i.e., age, culture, cognitive ability, maturity, developmental and functioning level), (2) support (family, social, therapeutic relationship), (3) personal beliefs about disclosure, (4) diagnostic characteristics (e.g., prevalence, public familiarity, current biological evidence, stigma), (5) how to provide a supportive disclosure (e.g., kid friendly language), and (6) potential benefits. Combined open-ended and quantitative results provide empirical support suggesting that psychologists, like psychiatrists and pediatricians, are more likely to disclose diagnoses to: (a) children of an American culture than those of a Chinese-American culture, (b) older (16 years old) children rather than younger children (6 years old), and (c) children with an intellectual ability in the Superior Range rather than those with an IQ in the Borderline Range. Psychologists' years of clinical experience also significantly predicted their disclosure practice. Psychologists with between 13-31 years clinical experience reported more diagnosis disclosure to children than did participants with 32 years or more of clinical service when presented with a client who was of an American decent, 16 years old, or had an intellectual ability in the Superior Range. The services that psychologists provide (i.e., counseling, diagnostic evaluations, or both) did not significantly predict disclosure practices. Taken together, the findings of this study may be the first step to facilitate the development of evidenced based guidelines for the disclosure of mental health diagnoses to children.