Lenalidomide and pomalidomide increase dendritic cell (DC) dependent T-cell expansion. IMiD-treated DC were loaded with ovalbumin, used in antigen presentation assays with OT-I or OT-II splenocytes and proliferation was measured by [H3]thymidine incorporation. A significantly higher CD8+ T-cell cross-priming was seen (35% and 47% higher than in antigen presentation assays containing 5 and 10 μm of lenalidomide-pre-treated DCs, respectively) compared with the DMSO control [P < 0·05 by repeated measures analysis of variance (anova) and Newman–Keuls, n = 7] and 43% higher in antigen presentation assays containing 10 μm pomalidomide-pre-treated DCs (a) (P < 0·001 by repeated measures anova and Newman–Keuls, n = 7). CD4+ T-cell priming was increased by 30% in 10 μm pomalidomide-pre-treated DCs (P < 0·05 by repeated measures anova and Newman–Keuls, n = 7) (b). Lenalidomide-pre-treated DCs had no effect on CD4 T-cell proliferation.