PURPOSE: To investigate the effect of mild cataract and its surgery on the ISCEV standard electroretinogram (ERG) by comparing pre- and postoperative ERGs elicited from fully dilated eyes. METHODS: Twenty-two patients participated. Each eye had cataract of grade 2 according to Emery-Little classification. None had complications during and after phacoemulsification and intraocular lens implantation. According to the ISCEV standard, pre- and 1-week postoperative full-field ERGs, dark adapted (DA) 0.01, DA 3, DA 3 oscillatory potentials (OPs), DA 10, and light adapted (LA) 3, and LA 3 flicker, were elicited from fully dilated eyes using skin electrodes. Photopic negative response (PhNR) 1 amplitude was measured from the baseline to the trough before the i-wave in the LA 3 ERG waveform. Statistical analysis was performed using SigmaPlot version 11.0 (Systat Software, Inc., San Jose, CA, USA). Pre- and postoperative data were compared using a paired t-test. Non-normally distributed data were evaluated using the Wilcoxon signed rank test. RESULTS: The pre- and 1-week postoperative amplitudes in each component were as follows: DA 0.01: 48.4 ± 19.5 µV and 57.1 ± 20.0 µV (p = 0.002), a-wave of DA3: 51.5 ± 14.8 µV and 58.3 ± 17.3 µV (p = 0.003), b-wave of DA3: 88.3 ± 27.5 µV and 101.5 ± 29.7 µV (p = 0.003), DA 3 ΣOPs (sum of DA 3 OP1, OP2, and OP3 amplitude): 30.7 ± 16.3 µV and 37.1 ± 21.9 µV (p < 0.001), a-wave of DA 10: 65.5 ± 18.8 µV and 74.2 ± 19.5 µV (p < 0.001), b-wave of DA 10: 95.5 ± 29.6 µV and 111.1 ± 29.9 µV (p < 0.001), a-wave of LA 3: 7.2 ± 2.6 µV and 8.2 ± 2.2 µV (p = 0.025), b-wave of LA 3: 30.6 ± 12.9 µV and 35.3 ± 12.7 µV (p = 0.003), PhNR1: 5.8 ± 2.5 µV and 5.5 ± 2.6 µV (p = 0.562), and LA 3 flicker: 25.4 ± 8.9 µV and 27.8 ± 8.6 µV (p = 0.039), respectively. The implicit time of all the components did not reveal significant differences before and after surgery. CONCLUSIONS: Cataractous lens removal and intraocular lens implantation may influence ISCEV standard ERGs, even if the cataract is relatively mild.