This case is reported because it is the only one of femoral aneurysm complicating subacute bacterial endocarditis in a child that is reported in the literature. REPORT OF CASE A boy, aged 10, was admitted to the Post-Graduate Hospital for tonsillectomy, May 24, 1929, with a history of frequent colds together with tonsillitis during the preceding winter. He had had measles, whooping cough, pneumonia, and appendicitis with appendectomy in 1926. On admission his heart was enlarged, the left border being about one-half inch outside the left nipple. The apex beat was heard in the fifth interspace, and a prolonged blowing systolic murmur was heard throughout the chest but with maximum intensity at the apex. The rate was 80 and regular. A tonsillectomy and adenoidectomy was done May 24, and there was an uneventful recovery. The child was not seen again until Feb. 20, 1930, when he was readmitted to the