Background: Keratoconus is a progressive disorder in which the cornea assumes a conical shape secondary to stromal thinning and protrusion. Both eyes are affected, at least on topographical imaging, in almost all cases. Collagen cross-linking (CXL) is a bioengineering technique to increase the mechanical stability of the cornea in corneal ectatic disorders such as keratoconus (KC). Endothelial changes were reported after CXL. Objective: To evaluate the corneal endothelial changes following cross linking for treatment of keratoconus using corneal specular microscopy and corneal volume measurements. Patient and methods: A prospective, non-randomized interventional case series was conducted on 20 eyes diagnosed with progressive keratoconus. Patients were evaluated for endothelial changes using corneal specular microscopy and for Keratometric and corneal volume measurements using Pentacam. Measurements were done preoperatively and 6 months postoperatively. This study was carried out during the period from January 2020 till July 2020 at al-Hussein university hospital. Results: The mean age of the studied patients was 20.50±0.51 years. Of total 10 patients, there were 3 males (30%) and 7 females (70%). There was significant reduction in K1, K2, K max, thinnest location pachymetry, corneal volume, endothelial cell density (CD) and hexagonal cells percentage (Hex%) postoperatively, while Coefficient of variation (CV%) changes were insignificant. Results showed that CD change and Hex% change had reverse proportional correlation with corneal volume change, while, central corneal thickness change has positive proportional correlation with corneal volume change. Conclusion: CXL significantly flattened keratoconic corneas with significant reported endothelial changes. The study could not confirm the value of corneal volume change as a potential indicator for widespread endothelial dysfunction after CXL.