RHD-CE-D hybrid alleles cause partial D or D-negative phenotypes depending on the crossing-over sites between RHD and RHCE . The RHD-CE(2-9)-D hybrid allele is the only hybrid form reported as D-negative in the Korean population. Here, we report the first Korean case of the RHD-CE(3-8)-D allele in a D-negative patient with heart failure. His blood sample was typed as D-negative by the automated microplate method (QWALYS-3 system; DIAGAST, France). Weak D test was weak positive, but false positive reactivity could not be excluded due to positive direct antiglobulin test. To confirm the RhD type, RHD genotyping was performed, and the RHD-CE(3-8)-D hybrid, known as D-negative allele, was identified. Upon the patient’s subsequent visit 7 months later, a follow-up RhD typing including an adsorption-elution test confirmed that the patient was D-negative.