Eosinophil‐produced cytokines have been shown to participate in the maintenance of antigen‐specific plasma cells (PC) in bone marrow (BM), suggesting that eosinophils are required in the development and/or maintenance of alloantibody responses posttransplant. To test this hypothesis, we sensitized eosinophil‐deficient ΔdblGATA1 mice and wild‐type (WT) control mice with allogeneic splenocytes or with allogeneic heart grafts and compared the kinetics and titers of serum donor‐specific antibodies (DSA), as well as BM and spleen CD130 + B220 low PC populations between groups. Spleen cells from naïve ΔdblGATA1 BALB/c mice contained higher percentages of PC than WT without detectable differences in BM PCs. After sensitization with allogeneic splenocytes, BALB/c ΔdblGATA1 mice contained fewer BM PCs but more splenic PCs compared to controls. These differences were associated with modestly lower titers of serum DSA 4 and 12 weeks after sensitization but secondary immunizations induced similar increases in both groups. Moreover, the kinetics and strength of DSA did not differ in WT and ΔdblGATA1 BALB/c mice transplanted with B6 cardiac allografts, nor did they differ in transplanted ΔdblGATA1 and WT mice on a B6 background. Therefore, eosinophils are not required for alloantibody formation or maintenance in mice and are thus unlikely to be effective targets for antibody desensitization.