OBJECTIVE To investigate the correlation between chromosome 13q14 deletion [del(13q14)] and chromosome 1q abnormality in multiple myeloma (MM). METHODS The bone marrow plasma cells of 48 previously untreated MM patients were purified by CD138 and magnetic cell sorting system, and interphase fluorescence in situ hybridization (I-FISH) was applied to detect the del(13q14) with D13S319 probe and the abnormalities of chromosome 1q with CEP1 SpectrumOrange probe in sorted MM cells. RESULTS Among the 48 MM patients, del(13q14) was observed in 22(45.8%) cases, the abnormalities of chromosome 1q were observed in 23 (47.9%) cases, among which 2 were 1q deletion and 21 were 1q duplication. The chromosome 1q abnormality was detected in 16 of the 22 cases of MM with del(13q14) and in 7 of the 26 cases of MM without del(13q14), and there was significant difference between the two groups (chi-square was 10.02, P was less than 0.01). CONCLUSIONS There is high frequency of chromosome 13q14 deletion and 1q abnormality in multiple myeloma. The chromosome 1q abnormalities are highly associated with 13q14 deletion.