Abstract Recently, at a case conference, one of my collegues made a slip of the tongue and referred to a 33-year-old male patient as a “boy.” This slip was recognized as significant, and it led to productive group discussion about this patient's immaturity, dependency, and general lack of adult masculine qualities. In a culture where we clearly “separate the men from the boys,” it is hardly surprising that this linguistic distinction is an important one. Boys early learn to look forward to becoming men, and encouragement to “Act like a man!” implies that one should strive for strength, independence, maturity, courage, and integrity. For men, it is evident that differences in language reflect differences in self-experience and experience of others. (Consider, for example, the difference between a “colored boy” and a “black man.”) The dictionary notes that the word “boy,” when applied to a young adult, suggests that the person in question lacks maturity and judgment, or is considered by the speaker to be an inferior individual. 1 In clinical settings, however, female patients are frequently referred to as “girls” regardless of whether they are 13 or 30. Further, I have noticed that when I confront my colleagues for blanketly labeling all females “girls,” many will use the term “gal” or “lady” (respectively, according to age) but assiduously avoid the word “woman.” Because the preferred use of either the term girl or the term lady is a ubiquitous phenomenon in this culture, the linguistic distinction is often seen as a mere cultural habit that is of no particular relevance for psychiatry. This is incorrect, however, for one's choice of language reflects one's unconscious assumptions, and for mental-health professionals it is imperative that such assumptions be recognized, made explicit, and understood. The task of this paper is to examine the assumptions underlying the preferred use of the terms girl and lady, to explore why this choice in language has been established and maintained, and to note the significance it may have in regard to treating patients.