To examine the short- and long-term influences of the Marmara earthquake, which occurred on August 17, 1999 in Turkey, on glycemic control and quality of life (QOL), HbA(1c) insulin requirement and QOL of 88 people with type 1 diabetes living in the quake zone were evaluated one year before (PreE), 3 months after (PostE) and one year after (FE) the earthquake. HbA(1c) levels and daily insulin requirements increased significantly at PostE (HbA(1c) from 7.4 +/- 1.3% to 8.5 +/- 1.8%, p<0.05; insulin from 0.58 +/- 0.2 IU/kg/day to 0.77 +/- 0.2 IU/kg/day, p<0.05). Mean total QOL scores at PostE were significantly lower than the scores obtained at PreE (62.7 +/- 17.3 vs 74.2 +/- 13.4, p<0.00 1). There were no significant differences between HbA(1c) levels and total QOL scores at PreE and FE. People with type 1 diabetes living in the same house after the earthquake and not having enough food supply were reported to have lower QOL than people moving to another house and having enough food supply after the earthquake (p = 0.014, p<0.0001, respectively). The Marmara Earthquake had a negative impact on the glycemic control and QOL of the subjects with type 1 diabetes for the short term but prequake scores might be achieved after a long period.