Aim of Work: To study the clinical outcomes of combined simultaneous femtosecond kerarings implantation and corneal collagen cross-linking in advanced keratoconus. Methods: A prospective study was conducted on 25 eyes of 33 patients were diagnosed as advanced keratoconus. The study population underwent combined simultaneous femtosecond kerarings implantation and corneal collagen cross-linking. Results were reported at the 1st, 3rd, 6th and 12th months post-operatively Results: a significant improvement was found in postoperative (UCVA) (BCVA) and (SER) started form the first month postoperatively and continued all over the year (P < 0,001). The flattest k (K1) the steepest k (K2) and the average k (Ka) showed marked decrease after 3 month and became just stable in next 3 months and increase slightly thereafter (P=0.001). Conclusions: Combined simultaneous femtosecond kerarings implantation and corneal collagen cross-linking is an effective method in treating cases with advanced keratoconus