We reviewed retrospectively 135 cases of serologically-confirmed psittacosis that were admitted to Fairfield Hospital between January 1, 1972 and March 31, 1986. The average age of the patients was 46 years. The majority (85%) of patients described a history of recent exposure to birds. The clinical features, investigations, treatment and subsequent response were analysed in 129 patients. Psittacosis was a well-defined illness that was characterized by an abrupt onset of fever, rigors, sweats, and prominent headache, and a mild dry cough which appeared late frequently. However, respiratory symptoms were absent in 18% of patients. Diarrhoea and sore throat were occasional complaints. Over 90% of cases had an abnormal chest x-ray film, or abnormal chest signs, or a combination of both. Most patients had a normal leukocyte count. Tetracycline drugs were used for treatment in 87% of the patients. Defervescence occurred in 92% of patients after 48 h of tetracycline treatment. There were no recrudescences of psittacosis and no fatalities. The clinical diagnosis of psittacosis can be made early usually, particularly in the presence of pneumonitis on a chest x-ray film and a positive history of bird contact. Treatment with doxycycline (100 mg twice a day for 14 days) is recommended.