Anchoring bias is a cognitive phenomenon in which the first available information becomes a rigid reference point that distorts the interpretation of subsequent data, even when this clearly contradicts the initial impression. This chapter illustrates the bias through the case of Emperor Frederick III, whose progressive dysphonia was persistently interpreted as a benign disease by the renowned otolaryngologist Morell Mackenzie, despite clinical and pathological evidence suggesting laryngeal cancer. The story reveals how an initial diagnosis functioned as an anchor, shaping therapeutic decisions, reinterpreting signs of deterioration, and generating conflicts between German and English specialists. The chapter reviews the main explanatory theories of anchoring, including anchoring-as-adjustment, selective accessibility, and cognitive load, and the factors that modulate its intensity, such as mood, experience, personality traits, overconfidence, and anchor presentation. Its effects on negotiation, price setting, group dynamics, and interpersonal relationships are also analyzed. Finally, examples of anchoring in surgical practice and mitigation strategies are presented, such as questioning the first impression, considering opposite alternatives, offering multiple starting points, and recognizing hidden anchors in the clinical context.