Purpose <p>To evaluate postoperative endothelial cell function and corneal transparency in patients who underwent deep anterior lamellar keratoplasty (DALK) due to keratoconus (KC), macular corneal dystrophy (MCD), lattice corneal dystrophy (LCD), or corneal scarring.</p> Methods <p>This retrospective study included 55 eyes of 55 patients who underwent DALK between 2014 and 2023 and 56 eyes of 56 healthy individuals as controls. Endothelial cell density (ECD) and cell morphology were assessed using specular microscopy, and corneal densitometry measurements were obtained using Pentacam at postoperative months 1, 6, and 12. Outcomes were compared between the patient and control groups and among diagnostic subgroups within the DALK cohort.</p> Results <p>At postoperative month 1, corneal densitometry values were significantly higher in the DALK group compared with the control group (<i>p</i> &lt; 0.0001). Endothelial cell density was significantly lower in the DALK group than in controls (<i>p</i> &lt; 0.0001). No significant difference in ECD was observed among the diagnostic subgroups (KC, MCD, LCD, and corneal scarring) (<i>p</i> = 0.367). In the MCD group, anterior and central 0–2&#xa0;mm densitometry values at postoperative month 1 were significantly higher than those in the KC and LCD groups (<i>p</i> = 0.026); however, no significant differences were observed at months 6 and 12.</p> Conclusions <p>Although endothelial cell density was reduced in all diagnostic groups after DALK compared with healthy controls, adequate endothelial cell function was preserved. The preservation of endothelial function in patients with macular corneal dystrophy indicates that DALK can be safely performed in this patient population.</p>