A case of sacrococcygeal teratoma, weighing 310 gms, is reported with a brief review of literature A 2 months old female baby(6,700 gms of body weight) was admitted with lower mid-abdominaK distension and voiding difficulty for 10 days before admission. About fetal head sized round mass, with fairly defined border, was palpated on lower mid- abdomen. Roentgenographic examinations(Intra-Venous Pyelography, Cystography 8h Barium enema) showed! A huge mass shadow in the pelvic cavity and lower abdomen, anterior and right side displacement. Of rectum and sigmoid colon, hydronephrosis and hydroureter due to distal ureteral stenosis by large pelvic mass, and anteriorly displaced bladder. The treatment of sacrococcygeal teratorna is surgical removal. The resected tumor consisted of various sized multiple cysts containing clear fluid, hair and fatty tissue grossly. Histologically, the tumor composed of tridermal origin, however, no evidences of malignancy were observed. At general surgery department of Ewha Womans University Hospital, good result was obtained in the surgical removal of sacroccygeal teratoma. A case is reported and the literature is reviewed.