To report the long-term outcome of early secondary intraocular lens (IOL) implantation following congenital cataract extraction in a large number of eyes. Data of aphakic children under 30 months of age who underwent secondary IOL implantation and had at least one year of follow-up after the surgery was reviewed. In all of the patients, a foldable three-piece acrylic IOL was implanted in the ciliary sulcus by the same surgeon using the same technique. The database studied included refractive and visual acuity (VA) outcomes and complications. Fifty patients (75 eyes) were included. The average age at the time of cataract extraction was 94.20 ± 44.94 days and 20.7 ± 6.0 months in the secondary IOL implantation. After 82.32 ± 48.91 months, the VA was 0.58 ± 0.35 LogMAR and the spherical equivalent was -2.20 ± 4.19 D. There was a negative correlation between a longer follow-up period and myopia at the SE measured (P = .001). The most frequent complications included glaucoma and corectopia. Performing the secondary IOL implantation ≤ 20 months of age was not a risk factor for glaucoma development (P = 0.095). Secondary IOL implantation under 30 months of age is an option for children with unsatisfactory management of the optic treatment. A predictable IOL power calculation and satisfactory visual outcomes compared to results of later secondary IOL implantation are possible.