Dermoid cysts (DCs) are subcutaneously located cystic masses that contain epithelium and adnexal structures. They are most commonly located in the ovaries and sacral region. Seven percent of DCs are found in the head and neck. Sublingual DCs may develop above the mylohyoid, presenting in the floor of the mouth or below it, causing a submental or submaxillary mass. We presented a case with a sublingual giant DC enlarged rapidly during pregnancy manifesting deglutition and mild respiratory problems. The growth of a DC of the neck may be accelarated in pregnancy period and may ensue severe symptoms challenging both mother and fetus. We proposed the removal of sublingual DCs before attempting to conceive to eliminate the risk of rapid growth of DC that results in respiratory and deglutition problems. (C) 2003 Elsevier Inc. All rights reserved.