Background: Adult-onset Still's disease (AOSD) is a febrile disorder of unknown aetiology characterised by typical spiking fever, evanescent rash, arthralgia and leucocytosis. Methods: According to the diagnostic criteria of AOSD, we identified 84 patients between 1990 and 2003. The aim of this study was to analyse the characteristics of AOSD in Turkish patients who were followed-up in a tertiary referral centre. Results: Of 84 patients of AOSD, 59 (70.2%) were female, 25 (29.8%) were male. Arthralgia (96.4%), fever (95.2%), arthritis (69%), sore throat (65.5%) and typical rheumatoid rash (59.5%) were the most common findings. The mean value of laboratory findings were as follows; C-reactive protein level of 11.59 +/- 6.81 mg/dl, erythrocyte sedimentation rate (ESR) of 89.05 +/- 31 mm/h, leukocyte count of 16,234.51 +/- 7785.2/mu l. Leucocytosis was present in 69 patients (84.15%). Forty-eight patients had a WBC count >= 15,000/mu l. Hypoalbuminaemia was present in 35 patients. Abnormal levels of aspartate aminotransferase and alanine aminotransferase were observed in 30 patients, whereas abnormal levels of alkaline phosphatase in 16 patients. Thirty-seven patients had an ESR value of more than 100 mm/h. Thirty-two patients had a ferritin value of more than 1000 ng/dl. Conclusion: High fever, sore throat, rheumatoid rash, polyarthritis, hyperferritinaemia (>= 1000 ng/ml), leucocytosis with a neutrophilic predominance, anaemia and hypoalbuminaemia were remarkable observations in the initial examination.