The term mixed connective tissue disease (MCTD) has been applied to a particular subset of patients with overlapping clinical features of systemic sclerosis, systemic lupus erythematosus, and polymyositis. Immune response to U1-ribonucleoprotein is the defining serological feature of MCTD. There are different organ and system involvements in MCTD including the heart, lung, kidney, muscle, joints, gastrointestinal, and hematologic involvements. Reports describing pregnancies in patients with MCTD are rare, and the results have been contradictory: a high risk of fetal loss and of disease exacerbation or no influence on fetus or mother. In MCTD, simultaneous pulmonary and renal involvement is very rare. In this paper, we report a case of MCTD with pulmonary involvement that developed scleroderma renal crisis after an abortion.