This study aimed to investigate the prevalence,clinical characteristics,and prognostic impact of 1p32.3 deletion in patients with newly diagnosed multiple myeloma (MM).A retrospective analysis was conducted on 411 patients with newly diagnosed MM;among which,270 received bortezomib-based therapies,and 141 received thalidomide-based therapies.Fluorescence in situ hybridization (FISH) was performed to detect six cytogenetic abnormalities,namely,del(1p32.3),gain(1q21),del(17p13),del(13q14),t(4;14),and t(11;14).Results showed that 8.3％ of patients with MM were detected with del(1p32.3) and had significantly more bone marrow plasma cells (P =0.025),higher β2-microglobulin levels (P =0.036),and higher lactate dehydrogenase levels (P =0.042) than those without del(1p32.3).Univariate analysis showed that patients with del(1p32.3) under thalidomide-based therapies were strongly associated with short progression-free survival (PFS) (median PFS 11.6 vs.31.2 months,P =0.002) and overall survival (OS) (median OS 16.8 vs.45.9 months,P ＜ 0.001).Multivariate analysis revealed that del(1p32.3) remained a powerful independent factor with worse PFS (P =0.006) and OS (P =0.016) for patients under thalidomide-based treatments.Patients with del(1 p32.3) under bortezomib-based treatments tended to have short PFS and OS.In conclusion,del(1p32.3) is associated with short PFS and OS in patients with MM who received thalidomide-or bortezomib-based treatments.