Case 1 was a 55 year old female whose primary complaint was pyrexia. Anamnesis consisted of a fever at a 39 degrees C level beginning on September 15, 1987 with headache and muscle pain. The patient was examined by a nearby physician. Despite taking medication, there was no break in the fever. The patient was examined and admitted to this institution on September 18. Case 2 was a 32 year old female whose primary complaint was pyrexia and an abnormal sensation in the pharynx. Anamnesis consisted of a fever at a 39 degrees C level beginning on February 13, 1989 and the manifestation of a cough beginning on February 17. Although the fever broke on February 20, as the abnormal sensation in the pharynx persisted, the patient was examined and admitted to this institution on February 21. Case 3 was a 42 year old male whose primary complaint was pyrexia. Anamnesis consisted of a fever of 38 degrees C, cough and a sensation of pressure in the right precordia beginning on November 18, 1989. The patient was examined and admitted to this institution on November 21. Chest X-rays revealed the presence of atypical pneumonia in all three cases. As a significant rise in antibodies to the Chlamydia of parrot fever was observed in the cases at the time of admittance as well as after admittance, treatment was begun by administration of Minocycline.(ABSTRACT TRUNCATED AT 250 WORDS)