Pregnancy rhinitis is defined as nasal congestion in the last 6 or more weeks of pregnancy, without other signs of respiratory tract infection and with no known allergic cause, with complete resolution of symptoms within 2 weeks after delivery. Pregnancy rhinitis occurs in approximately one-fifth of pregnancies, can appear at almost any gestational week, and affects the woman and possibly also the fetus. The pathogenesis of pregnancy rhinitis is not clear, but placental growth hormone is suggested to be involved. Smoking and sensitization to house dust mites are probable risk factors. It is often difficult to make a differential diagnosis from sinusitis: nasendoscopy of a decongested nose is the diagnostic method of choice. In some cases ultrasound or x-ray may be necessary. Sinusitis should be treated aggressively with increased doses of beta-lactam antibiotics and antral irrigation. Nasal decongestants give good temporary relief from pregnancy rhinitis, but they tend to be overused, leading to the development of rhinitis medicamentosa. Corticosteroids have not been shown to be effective in pregnancy rhinitis, and their systemic administration should be avoided during pregnancy. Nasal corticosteroids may be administered to pregnant women when indicated for other sorts of rhinitis. Nasal alar dilators and saline washings are safe means to relieve nasal congestion, but the ultimate treatment for pregnancy rhinitis remains to be found.