The relationship between focal segmental glomerulosclerosis (FSGS) and pregnancy is complex and not completely elucidated. Pregnancy in patients with FSGS poses a high risk for complications, possibly due to hemodynamic factors, imbalance between angiogenic and antiangiogenic factors, and hormonal conditioning. Although poor clinical outcomes associated with collapsing FSGS are common outside of pregnancy, the prognosis during pregnancy is not well documented. We report 3 patients who developed collapsing FSGS during pregnancy, 2 of whom had presumed underlying FSGS.