Thalidomide and bortezomib are extensively used to treat elderly myeloma patients. In these patients, treatment-related side effects are frequent and full drug doses difficult to tolerate. We retrospectively analyzed data from 1435 elderly patients enrolled in 4 European phase III trials including thalidomide and/or bortezomib. After a median follow up of 33 months (95%CI: 10-56 months), 513 of 1435 patients (36%) died; median overall survival was 50 months (95%CI: 46-60 months). The risk of death was increased in patients aged 75 years or over (HR 1.44, 95%CI: 1.20-1.72; P<0.001), in patients with renal failure (HR 2.02, 95%CI: 1.51-2.70; P<0.001), in those who experienced grade 3-4 infections, cardiac or gastrointestinal adverse events during treatment (HR 2.53, 95%CI: 1.75-3.64; P<0.001) and in those who required drug discontinuation due to adverse events (HR 1.67, 95%CI; 1.12-2.51; P=0.01). This increased risk was restricted to the first six months after occurrence of adverse events or drug discontinuation and declined over time. More intensive approaches, such as the combination of bortezomib-thalidomide, negatively affected outcome. Bortezomib-based combinations may overcome the negative impact of renal failure. Age 75 years or over or renal failure at presentation, occurrence of infections, cardiac or gastrointestinal adverse events negatively affected survival. A detailed geriatric assessment, organ evaluation and less intense individualized approaches are suggested in elderly unfit subjects.