Aim: The aim of the study was to investigate effectiveness of corneal collagen cross-linking treatment in patients with progressive keratoconus. Patients and Methods: Ten patients (6 female and 4 male) who showed progression in the parameters of Keratoconus were included in the study. Complete ophthalmological examinations including uncorrected and best-corrected visual acuities (UCVA and BCVA), slit-lamp anterior and posterior segment investigation and intraocular pressure was performed in all patients. Corneal topographic measurements were done by Sirius Corneal Topography system. All patients underwent an intervention of corneal collagen cross-linking procedure with riboflavin and UV-A. Results: Sim K max value of all patients in topographic measurement decreased (mean 0,95±0,22 D) after 6 month follow-up. The value of sim K min decreased (mean 0.39 D) in 8 patients, while it showed no change in 2 patients (20%). A decrease of mean of 10,1±1,37μm central corneal thickness was observed. In 6 eyes (60%), BCVA showed improvement when compared to the baseline values, while BCVA in 4 (40%) eyes remained stable during the follow-up period. Conclusion: Corneal collagen cross-linking treatment as a first applications of our clinic using Apollon device seems to be effective in prevention of keratoconus progression according to our experience in our small series. Long-term, prospective, large studies are needed to display the long-term effectiveness of this treatment.