We evaluated the clinical results of lenalidomide (Len) as a compassionate salvage therapy in refractory/relapsed multiple myeloma (MM) patients. A nationwide multi-centre, retrospective research study was performed to evaluate clinical data from patients with advanced MM for which compassionate use of lenalidomide was requested. The primary endpoints were the overall response rate (ORR) and the time to progression (TTP). Secondary objectives included safety and overall survival (OS) since starting of lenalidomide therapy. Data collected from the Spanish Compassionate Use Registry included 111 patients treated in 2006-2008. The median (range) number of previous treatment lines was 3 (1-8). The median duration of lenalidomide treatment while on study was of 4.9 months (1-18). Dexamethasone was given concomitantly with Len in 89% of patients. The ORR was 66% (4% of patients had stringent complete, 11% complete and 11% very good partial responses). Median TTP and OS were 13.0 and 17.4 months, respectively. The depth of response was significantly associated with a longer OS. Toxicity, mainly myelosuppression, was predictable and manageable with Len dose adjustments and cytokine support. Lenalidomide as salvage compassionate therapy in refractory/relapsed MM showed, in this series of heavily pre-treated patients, similar efficacy to that reported in pivotal clinical trials with acceptable tolerance.