Osteoporosis is mainly a problem in postmenopausal women. However, we had a case of postpartum compression fracture associated with osteoporosis. A 42-year-old multiparous woman had undergone tertiary cesarean section without complications 1 month before. She was breast-feeding her baby and had no other bone-related complication history. She did not exercise on a regular basis. She experienced back pain abruptly and was diagnosed with a recent compression fracture of T12, L1, and L3. We evaluated this rare case of postpartum osteoporosis and compression fracture.