There is a lack of treatment guidelines for how to address the impact of nutrition on clients’ mental health. Prior research is limited regarding psychologists’ practices of nutrition counseling and has mostly focused on practices of dieticians and medical doctors. The purpose of this study was to examine psychologists’ beliefs and attitudes about nutrition counseling, amount of training and use of nutrition counseling, self-rated knowledge in the use of nutrition counseling and perceived benefits and barriers to using nutrition counseling. Data was collected using an online survey of 76 licensed psychologists’ training in nutrition and use of nutrition counseling. Findings show that most of the psychologists talk to their clients about nutrition, nearly half report using nutrition counseling, but few received training in nutrition while in graduate school. A statistically significant difference was found between those who use nutrition counseling and those who do not regarding self-reported knowledge, belief about therapy, benefit of outcome, importance of nutrition in the context of mental health, importance of discussing nutrition with clients and confidence as a barrier to using nutrition counseling in practice. A statistically significant difference was found between those who have training in nutrition and those who do not regarding self-reported knowledge, benefit of outcome, and importance of discussing nutrition with clients. The relationship between use of nutrition counseling and training in nutrition was statistically significant. As might be expected, a larger proportion of those who have training in nutrition use nutrition counseling than the proportion of those without training. The result highlights the need for a collaborative approach to client care. Psychologists reported several themes, including need for more training and guidelines for psychologists’ use of nutrition counseling.