Focal segmental glomerulosclerosis (FSGS) is a leading cause of nephrotic syndrome in adults and a major contributor to chronic kidney disease progression. We conducted a retrospective, single-center study including 134 adults with biopsy-proven FSGS and nephrotic syndrome, hospitalized at the Internal Medicine A Department of Charles Nicolle Hospital between 1983 and 2022. The study aimed to describe clinical, histological, and outcome profiles and identify predictors of poor renal prognosis. The mean age at diagnosis was 35.3 ± 14.6 years, with a male predominance (63.4%). Edema was the most frequent presenting symptom (79.1%), and C3 deposits. 46.3% had renal insufficiency at presentation. Light microscopy revealed flocculo-capsular synechiae in 84.9% of biopsies. Among 28 biopsies classified using the Columbia classification, 17 were Tip lesions and 11 collapsing variants. Immunofluorescence was positive in 87%, most commonly with segmental IgM and First-line corticosteroid therapy achieved complete remission in 42.5%, partial remission in 23%, and steroid resistance in 34.5%. Relapses occurred in 30.1% of cases. Second-line immunosuppressive therapy was used in resistant or dependent cases. Chronic kidney disease developed in 53.7% of patients, with 33.6% progressing to stage 5 CKD. In multivariate analysis, higher proteinuria at 4 months (OR=1.786) and steroid resistance (OR=3.812) predicted progression to stage 5 CKD, whereas complete remission (OR=0.204) and the tip lesion variant (OR=0.087) were associated with favorable renal outcomes.