In lower-risk myelodysplastic syndromes (MDS) with del(5q), lenalidomide induces erythroid responses associated with better survival. In a phase II, single-arm trial, 45 patients with anemia and lower-risk del(5q) MDS received lenalidomide 10 mg/day to evaluate quality of life (QoL) changes, measured by QOL-E, safety, responses and survival. Lenalidomide was well tolerated, with 80% completing ≥ 24 weeks of treatment. Earlier study discontinuation was related to disease progression (n = 5), death (n = 1) and withdrawal of consent (n = 3). Within 24 weeks, 82% obtained erythroid responses, durable in 69% at 52 weeks. Cytogenetic responses occurred in 29 patients (64%), with 10 patients achieving a complete cytogenetic response. QoL-E scores correlated with hemoglobin levels and improved in erythroid responders. Erythroid responders had an 86% reduced risk of disease progression and an 80% reduction in mortality risk compared with non-responders. These findings corroborate earlier studies and give further support to the use of lenalidomide in lower-risk MDS and del(5q).