Introduction: Effectiveness Evaluation of One-Day Simultaneous Bilateral Cataract Surgery (SBCS) Comparing to the Cataract Surgery Performed on Each Eye Separately After a Lapse of Time Material and Methods: The cohort of 100 patients (200 eyes) consisted of two groups: In the Group1, there were 50 patients (100 eyes) who underwent One-day Simultaneous Bilateral Cataract Surgery (SBCS). The Group 2 consisted 50 patients (100 eyes) who had the surgery on one eye first, and later on the fellow eye. The course of the surgery, peroperative and postoperative complications were evaluated. The patients from the Group 1 were examined at the first postoperative day. In the next course, all patients were examined one week, one month, and 3 months after the surgery. In the postoperative phase were, besides the complications, the final visual acuity and refraction and its deviations from the target refraction followed up. Results: Course of the surgery, peroperative and postoperative complications are comparable in both groups. Endophthalmitis, or other more serious postoperative complications did not appear in either group. Three months after the surgery, the uncorrected visual acuity (UCVA) 0.8 and better in the Group 1 had 75 % of patients, and in the Group 2 also 75 % of patients. The UCVA 0.5 and better in the Group 1 had 95 % of patients; in the Group 2 it had 90 % of patients. The best-corrected visual acuity 0.8 and better had in both groups 95 % of patients. The final refraction after 3 months in the Group 1 was –0.15 ± 0.91 (-0.12); -3.37; 2.00. In the Group 2 the final refraction after 3 months was –0.08 ± 0.91 (0.00); -3.25; 2.75. Conclusion: The results are showing that both groups of our cohort are comparable. The One-Day Simultaneous Bilateral Cataract Surgery (SBCS) is, from the surgical point of view, equally safe and effective as classically performed cataract surgery.