The frequency and prognostic relevance of translocations t(11;14) and t(4;14), the most common translocations involving the immunoglobulin heavy chain (IgH) gene in multiple myeloma (MM), were investigated in 128 patients treated with intensive chemotherapy and autologous stem cell transplant. Myeloma cells were identified by cytoplasmic light chain immunofluorescence combined with fluorescence in situ hybridization (cIg-FISH) for detection of translocations t(11;14) and t(4;14). Overall, t(11;14) was detected in 16 of 125 (12.8%) and t(4;14) in 15 of 120 (12.5%) patients. Progression-free and overall survivals were similar for patients with or without t(11;14). However, patients with t(4;14) had significantly shorter progression-free (median 9.9 months vs. 25.8 months; P = 0.0003) and overall survivals (median 18.3 months vs. 48.1 months; P < 0.0001) than patients without t(4;14). The t(4;14) was associated with IgA and t(11;14) with light chain MM. There was no association between the t(11;14) or t(4;14) and other biological parameters including age, gender, haemoglobin, beta-2 microglobulin, C-reactive protein, calcium, creatinine, albumin, or the percentage of bone marrow plasma cells. Multivariate analysis identified t(4;14) as the only adverse prognostic factor for both progression-free survival and overall survival. Our results indicate that the t(4;14) detected by cIg-FISH is associated with a poor prognosis in MM patients receiving intensive chemotherapy and autotransplant.