Background: The morphometric results after breast augmentations are generally understood to be clinically different between trans(gender) and cis(gender) women. The objective of this study was to establish these morphometric differences between the augmented breasts of trans and cis women and their implications for preoperative planning and expectation management of trans women. Methods: A single-center, observational cross-sectional study was conducted. Three-dimensional images (VECTRA) of the chest were taken and used to measure preset morphometric parameters. Subsequently, several proportional morphometric outcome variables were calculated. We compared body, breast, and nipple dimensions and their interdependence between trans and cis women. The main outcome sets were (1) the relative dimensions of the chest, (2) the position of the breasts relative to the chest, (3) and the position of the nipple relative to the breast and nipple size. Results: A total of 22 transgender and 22 cisgender women were included. The results showed that the breasts of the trans women were positioned more cranial. Furthermore, the nipple-areola complexes (NAC) were significantly smaller and positioned relatively more latero-cranial on the breasts. Conclusions: Morphological characteristics of augmented breasts differ significantly between trans and cis women. The results of this study identified distinct differences between the augmented breasts of trans and cis women. Because of the apparent differences in results, surgical considerations, expectation management, and shared decision-making should play an even more pronounced role in breast augmentations in trans women. Level of evidence: Level III, risk/prognostic study.