A review was made of the records of 27 patients admitted to National Jewish Hospital who developed or experienced a reactivation of pulmonary tuberculosis during pregnancy or the first 12 month post partum. Sixteen patients had drug-resistant disease, and 11 had drug-susceptible disease. The drug-resistant group had more extensive radiographic abnormalities(p less than 0.01), longer sputum conversion times (p less than 0.05), and a higher incidence of pulmonary complications and death (p = 0.05). Patients with tuberculosis associated with pregnancy have the same clinical presentation as nonpregnant patients. Tuberculosis during pregnancy should be treated, and the drugs that appear to be safest for the fetus include isoniazid, para-aminosalicylic acid, ethambutol, and rifampin.