Studies from allied professions suggest that intentional nondisclosure in clinical supervision is common; however, the types of intentional nondisclosure and reasons for nondisclosure have yet to be examined in an adequate sample of counselors-in-training (CITs). The current study examined intentional nondisclosure by CITs during their onsite supervision experience. We utilized content analysis to examine examples of intentional nondisclosure. Sixty-six participants provided examples of intentionally withholding information from their supervisors they perceived as significant. The most common types of information withheld were negative reactions to supervisors, general client observations, and clinical mistakes. The most common reasons cited were impression management, perceived unimportance, negative feelings, and supervisor incompetence. We offer implications for both supervisees and supervisors on how they might mitigate intentional nondisclosure; for example, we present strategies to address ineffective or harmful supervision, discuss techniques to openly address intentional nondisclosure, and explore ways to integrate training on best practices in clinical supervision.