Background <p>Advances in surgical technology and evolving beauty standards have increased interest in aesthetic surgery, especially rhinoplasty. A detailed understanding of nasal anatomy, particularly the nasal base, is essential for improving aesthetic and reconstructive outcomes. This study aimed to classify nostril and nostril sill types in the Turkish population, identify sex-based morphological differences, and provide reference data for preoperative planning.</p> Methods <p>This study included 227 medical students (124 females, 103 males) from Kütahya Health Sciences University. Standardised photographs were taken from frontal, lateral, and hyperextended views at a 2-meter distance. Morphometric measurements were performed using the ImageJ software.</p> Results <p>All nasal dimensions were significantly greater in males than females (<i>p</i> &lt; 0.05). The most common nostril sill type among both sexes was Type 3, whereas Type 1 was the most common overall. However, no statistically significant relationship was found between sex and nostril sill type.</p> Conclusions <p>The morphometric features of the nasal base in Turkish society differed significantly in size parameters according to sex, whereas nostril and nostril sill types were similarly distributed between genders. These findings provide valuable reference data for personalised and ethnically appropriate planning in nasal surgery, especially male rhinoplasty, and contribute to the literature on nasal base morphology.</p> Level of evidence <p>Not gradable.</p>