Diagnosing undifferentiated connective tissue disorder (UCTD) is a difficult process. On the surface, UCTD often mimics the symptoms of other more common conditions, such as pulmonary embolism. To make matters worse, a delayed or misdiagnosis could have serious implications for the patient's health. Here we present a case of a 45-year-old female, with complaints of shortness of breath and chest pain and was suspected as a case of pulmonary embolism but ended being diagnosed with probable undifferentiated connective tissue disorder.