Background <p>Eyebrows play a crucial role in facial aesthetics and emotional expression. Although eyebrow transplantation and reconstruction have gained popularity, a standardized classification system and ideal aesthetic parameters for East Asian eyebrows remain undefined.</p> Methods <p>A retrospective image analysis was conducted on 1,482 East Asian participants (1,043 males, 439 females) from multiple medical institutions. Eyebrow morphology was measured using Photoshop-assisted digital analysis. Independently, a novel eyebrow classification system was developed, categorizing eyebrows into 12 distinct types. Additionally, a cross-sectional study of 513 participants (146 males, 367 females) was conducted using AI-generated facial images to assess preferences for eyebrow shape and characteristics using a 5-point Likert scale.</p> Results <p>Among males, the triangular straight eyebrow was the most preferred, whereas females favored the smooth arched eyebrow. The ideal eyebrow peak was positioned on or outside the lateral canthus, with an optimal eyebrow peak height-to-intercanthal distance (HBP/ICD) ratio of 1.2. Males exhibited significantly greater eyebrow width-to-intercanthal distance (EW/ICD) ratios (0.4–0.5) and denser eyebrow hair, whereas females had a preferred EW/ICD ratio of 0.25–0.35 (<i>p</i> &lt; 0.001).</p> Conclusions <p>This study provides quantitative morphological data and a standardized eyebrow classification system for East Asians, offering clinical guidance for eyebrow transplantation and reconstruction. These findings enhance the understanding of East Asian eyebrow aesthetics and provide a valuable reference for personalized surgical design.</p> Level of Evidence IV <p>This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors <a href="http://www.springer.com/00266">www.springer.com/00266</a>.</p>