Prior to novel targeted agents for chronic lymphocytic leukemia (CLL), the best chemoimmunotherapy regimen in patients with non-del(11q) disease was unclear. The role of lenalidomide was also not defined. This phase 2 study randomized 342 untreated patients with non-del(11q) CLL requiring therapy to fludarabine plus rituximab (FR; n = 123), FR plus lenalidomide consolidation (FR+L; n = 109), or FR plus cyclophosphamide (FCR; n = 110) and compared 2-year progression-free survival (PFS) rates of each to the historical control rate with FC (60%). Patients with del(11q) in at least 20% of pretreatment cells continued with FCR (n = 27) or were reassigned to FCR+L (n = 31) and excluded from the primary analysis. Among non-del(11q) patients, 2-year PFS rates were 64% (90% confidence interval [CI], 57-71; FR), 72% (90% CI, 65-79; FR+L), and 74% (90% CI, 66-80; FCR); FR+L and FCR had rates significantly greater than historical control. Median PFS was significantly shorter with FR compared with FR+L (P = .04) and FCR (P < .001): 43 (95% CI, 33-50), 61 (95% CI, 45-71), and 97 (95% CI, 61 to not reached) months, respectively. Median follow-up was 73 months and median overall survival (OS) was only reached with FCR (101 months; 95% CI, 96 to not reached). With FR+L, the risk of death decreased over time and was lower than with FR at later time points (P = .01), but not significantly different from FCR (P = .21). Future studies incorporating short courses of lenalidomide into other novel treatment regimens are justified.