Purpose: To evaluate the influence of the pupil size on clinical results and objective parameters of optical quality of the Tecnis� ZCB00. Setting: Centre of Ophthalmology, Eberhard-Karls University T�bingen, Germany. Methods: In this study 51 eyes were implanted with a Tecnis� ZCB00. Postoperatively, best-corrected (BCVA) and uncorrected visual acuity (UCVA) were assessed. Total spherical aberration and corneal spherical aberration for optical zones of 3, 4, 5, and 6 mm was measured Contrast sensitivity and depth of focus were evaluated with a 3 mm and 5 mm pinhole (PH). Results: Mean follow-up was 3.0�0.4 months. Mean UCVA and BCVA were 20/25�8 letters and 20/18�4 letters, respectively. BCVA both with a 3 and a 5 mm PH was 20/18�4 letters. The corneal spherical aberration was 0.02�0.01 �m, 0.06�0.03 �m t, 0.14�0.09 �m and 0.27�0.22 �m for 3, 4, 5 and 6 mm optical zone. Mean total spherical aberration was -0.01�0.02 �m, 0.0�0.03 �m, 0.0�0.06 �m and 0.0�0.08 �m, for 3, 4, 5 and 6 mm optical zone, respectively. Contrast sensitivity was not statistically significant different with a 5 mm or 3 mm PH. Also, the defocus curves with a 3 mm and a 5 mm PH were not statistically significant different. Conclusion: The aspheric profile of the TECNIS� 1-Piece reduces total spherical aberration to virtually zero at all pupil sizes from 3-6 mm. Thus, visual acuity, contrast sensitivity, refraction and defocus curve show the same good results at large pupil sizes compared to small pupil sizes.