Infantile myofibromatosis is a disorder of mesenchymal tumors that usually presents within the first 2 years of life. Most patients initially present because of the presence of visible or palpable subcutaneous tumors. We report a case of a fussy 5-week-old infant who presented to an emergency department with bilateral femur fractures initially thought to be due to nonaccidental trauma or a metabolic bone disorder. She was ultimately diagnosed after admission with infantile myofibromatosis after taking an extensive family history and after further laboratory and radiologic evaluation. There are no previously published cases of undiagnosed infantile myofibromatosis presenting to the emergency department, especially with multiple long bone fractures.