Purpose To assess surgical, visual, refractive, and aesthetic outcomes 13 years after mersilene mesh frontalis sling (MMFS) operation for severe unilateral congenital ptosis performed in 10 infants before 1 year of age. Methods Longitudinal follow-up of an interventional case series by structured ocular examinations, external photographs, and questionnaire-based interviews.Results Mean age at surgery was 6.9±2.7 months. After a mean follow-up of 13.0±0.6 years, one patient (10%) had recurrent ptosis with the upper lid 2 mm below the superior limbus at 3 months postoperatively. Best-corrected visual acuities were within two Snellen lines between the two eyes in all patients. Astigmatic errors were 1.20±1.00 D and 1.10±1.70 D between operated and unoperated eyes. Four patients had 2 mm lid lag on down-gaze and one of them had 2 mm lagophthalmos. Mean satisfaction scores (scale of 1 to 100) for lid position, cosmesis, function, and to the procedure were 83.3 ± 11.8, 77.0±22.9, 89.4±5.5, and 86.8±6.3, respectively. No case of overcorrection, sling extrusion, stitch granuloma, or exposure keratopathy was noted. Conclusions In view of the low recurrence rate (10%) and absence of serious complication or need for revision after 13 years, the use of MMFS seems effective and feasible in infants less than 1 year old. Achieving compatible long-term stability, satisfactory aesthetic, and visual outcomes, MMFS may offer an alternative to delaying operations for autogenous fascia lata harvesting in infants requiring early ptosis correction.