The present study is concerned with impression formation in a context in which the information about others is limited and at the same time private by its very nature. We examined the accuracy of judges’ ratings of target individuals’ basic personality traits, affective traits, and assertive self-presentation tactics based on the natural stream of thought of the latter. Furthermore, we explored the moderating role of self-presentation in accurate evaluations of others. A group of 86 participants recorded their natural stream of thought, which then served as the basis for the judges’ ratings. The participants also completed self-report measures of basic personality traits, affective traits, and assertive self-presentation tactics. The results partially confirmed that it is possible for judges to form an accurate impression of target individuals’ personalities in a context in which the judges possess a small amount of relatively private information about the target individuals. It was even possible for the judges to detect the target individuals’ self-presentation tactics, particularly self-promotion. In addition, individuals who use self-promotion and exemplification in a private context are often viewed differently than those who do so less often.