Background: Diabetes technology is a fundamental part of modern diabetes therapy. Its widespread usage is associated with an increasing amount of “diabetes technology waste.” The aim of this study was to quantify this waste in a real-world situation in a specialized diabetes practice in Germany. Methods: Eighty patients with diabetes and insulin treatment participated and collected all of their therapy-associated waste for three months. Their attitude toward sustainability of antidiabetic therapy, waste generation, and their own waste reduction/separation behavior was surveyed. Results: In total, 23 707 pieces of therapy-associated waste were collected. They comprised 5362 test strips, 630 glucose sensors, 14 619 needles, 519 insulin cartridges, 599 pens, and 1463 pieces of aids for insulin pump therapy. Type and quantity of the collected waste depended on the type of diabetes and the respective therapy, ie, multiple daily injections, usage of glucose sensors, or pump therapy. Most participants (92%) were surprised by the amounts of waste and reported an increased awareness toward the resource consumption of their therapy (87%). The survey indicated an enhanced interest in waste separation (94%) and a demand for the reduction and recycling of devices/aids (93%). Conclusions: Our data revealed the amount and complexity of the waste generated by modern diabetes therapy. Extrapolating these data, it can be estimated that around 1.2 billion pieces of diabetes technology waste are generated in Germany per year. The major concern of the study participants was the limited number of recycling options. A clear demand for improved sustainability of the medical products was expressed.