Occipital alopecia after Open Heart Surgery under the Cardiopulmonary bypass is an uncommon minor complication. We had experienced Occipital alopecia in 6 cases after Open Heart Surgery. The cause of the alopecia was transient circulatory disturbance due to pressure effect of the patient`s head and intraoperative hypotension. The prodromal symptoms of the alopecia were erythema, itching, and watery discharge, but some patients showed non-specific symptoms. The common site of the alopecia was right occipital region and the size was 2-4 cm in diameter. The regrowth of the hair was completed at postoperative 3 to 5 months without specific treatment except conservative treatment. Fortunately the postoperative alopecia is a self-limiting condition, and spontaneous regrowth of hair is the rule without other complications.