There have been a few reported cases of immune hemolytic anemia induced by ceftriaxone. We encountered a patient with immune hemolytic anemia that seemed to be stimulated by a degradation product of ceftriaxone. The patient's direct antiglobulin test was positive only for C3d, and no ceftriaxone-dependent antibodies were detectable in the patient's serum. To demonstrate the presence of the ceftriaxone-induced antibodies, an ex-vivo antigen in urine was obtained from the patient. In addition, we prepared a 1 mg/mL suspension solution of ceftriaxone, and group AB serum as a complement source. Using several combinations of the above reactants, the indirect antiglobulin test was performed. Only the indirect antiglobulin test using the patient's serum with the ex-vivo urine antigen was found to be positive. Other combinations were not reactive. To our knowledge, this is the first reported case in Korea, in which the causative antibody appeared to be stimulated solely by a degradation product of ceftriaxone.