Glycemic and body weight control are two outstanding goals in the treatment of patients with type 2 diabetes that often are not appropriately achieved. This observational study evaluates whether treatment by quality controlled diabetes centers generates an improvement in this regard and focuses on associations with different therapies. Data of 9.294 type 2 diabetic patients (mean age 66.9±11.6 years, mean diabetes duration 12.4±9.2 years) from 103 German diabetes centers were assessed by a standardized, prospective, computer-based diabetes care and outcome documentation system (DPV-Wiss-database). Therapeutic concepts included lifestyle intervention (n=1.813), oral antidiabetics (OAD, n=1.536), insulin (n=4.504) and insulin plus OAD (n=1.441). HbA1c and body weight were compared before and after a stable therapeutical period of 1.07±0.3 years. Change in HbA1c (%): all patients 7.4±1.6-7.0±1.3, lifestyle intervention 7.5±1.9-6.9±1.5, OAD 6.7±1.1-6.5±1.0, insulin 7.6±1.6-7.2±1.4, insulin plus OAD 7.5±1.5-7.2±1.3; each p≤0.05. Change in body weight (kg): all patients +0.08±0.07, n. s.; lifestyle intervention -0.28±0.20, OAD -0.56±0.13, each p<0.05 [metfomin -0.77±0.21, sulfonylurea drugs -0.75±0.34, each p<0.05; glitazones +0.62±0.70, α-glucosidase inhibitors -0.22±0.76, each n. s.], insulin +0.27±0.10, insulin plus OAD +0.63±0.14, each n. s. In summary, lifestyle, metformin or sulfonylurea drug treatment resulted in HbA1c-values below 7.0% plus a significant weight reduction. Insulin treatment-associated concepts resulted in HbA1c-values slightly above 7.0% without body weight alterations. These "real life" data underline that a specialised and quality controlled diabetes care is able to achieve significant treatment results even in patients with disease progression and a high proportion of insulin therapies.