AIM: To evaluate and compare the clinical outcomes with a diffractive bifocal and trifocal intraocular lens (IOL) during a 12-month follow-up. METHODS: Prospective comparative study including 75 eyes of 38 patients (44-70y) undergoing uneventful cataract surgery. Each patient was randomly assigned to one type of IOL, bifocal (35 eyes) or trifocal (40 eyes). Visual, refractive, and contrast sensitivity changes were evaluated in a 12-month follow-up. The binocular defocus curve was also measured at 12mo postoperatively. RESULTS: No statistically significant differences between groups were found in postoperative uncorrected and corrected distance visual acuities (P≥0.276). Postoperative corrected near visual acuity (33 cm) was significantly better in the trifocal group during all follow-up (P≤0.004) as well as 6-month uncorrected near (P=0.008) and distance-corrected near visual acuities (P=0.016) (33/40 cm). Significantly better uncorrected intermediate and distance corrected-intermediate visual acuity were found during all follow-up in the trifocal group (P<0.001), which was consistent with differences among groups in binocular defocus curve. Differences among groups in contrast sensitivity were minimal, being only significant at 6 months for some low to medium spatial frequencies (P≤0.006). CONCLUSION: Bifocal and trifocal diffractive IOLs are able to provide an effective visual restoration which is maintained during a 12-month follow-up, with a clear benefit of the trifocal IOL for the intermediate vision.