The impact and complex nature of keeping secrets deserves greater scrutiny within psychoanalysis. While the capacity to keep a secret is a developmental achievement that furthers conscious choice and healthy boundary setting between self and others, an individual’s need for privacy must be distinguished from untoward costs of collusion and concealment. Clinical case material shows that not all secrets are unconscious or multilayered, as assumed in most of the psychoanalytic literature. Nonetheless, in these cases deleterious effects to psyche and soma took root. These patients assumed that their secret was irreparably destructive to an essential object relationship; shame, guilt, narcissistic vulnerability, unconscious identification with an injured party, and developmental deficit were other factors found to undergird this mode of pathogenic dissembling. Two clinical examples also demonstrate that embodied countertransference reactions may herald the revelation of a secret in treatment that had been hidden, but in plain view. Secrets appear to exert their profound psychological and physical effects on patient and analyst by biological mechanisms that are as yet poorly understood but are readily observed in clinical practice. Psychoanalysts who keep in conscious awareness both the adaptive value and the potential costs of maintaining the confidences of others over the course of a career are better positioned to assist their patients and themselves in rendering essential self-care.