Purpose: Providing data on the late diagnosis and surgical treatment of patients who underwent surgery for total unilateral congenital cataract. Methods: Systematic retrospective review of the medical record of all patients between 0 and 16 years old with total unilateral congenital cataract who underwent surgery at Fundación Vision between January 2010 and July 2012. Results: Medical records of 37 patients (51 % females) were studied, age was 7.4 (± 4.9) years (average ± SD) and 62% lived on Departamento Central (the most populated region from Paraguay). A total of 97.3% patients underwent late surgical treatment and 86.5% received a late diagnosis. The average time elapsed between the diagnosis and the surgical treatment was one month, and 62.2% of the patients underwent surgery within six months from the diagnosis. Conclusion: This study evidences that most of the patients in our series had a late treatment as a result of a late diagnosis. Based on these results we recommend establishing strategies to improve the early detection and surgical treatment of the newborns.