We used a combination of DNA-microarray and tissue-microarray (TMA) analyses to identify markers that could be routinely used to predict the outcome of diffuse large-B-cell lymphoma (DLCL) patients. Gene expression profiling was performed using DNA-microarrays on 52 tumour biopsy samples [31 DLCL and 21 follicular lymphomas (FL)] from 48 patients (28 DLCL and 20 FL). T-cell leukemia/lymphoma-1A (TCL1A) mRNA overexpression was correlated with relapse in DLCL patients. TMA analysis was applied on a distinct series of 36 formalin-fixed, paraffin-embedded DLCL samples and showed that TCL1A immunoexpression was correlated with either higher relapse (p=0.02) or lower 5-year overall survival (p=0.009) rates. Moreover, the prognostic value of TCL1A was independent from IPI in our series. Our data suggest that TCL1A immunodetection is an independent marker of adverse outcome that could be used in routine settings for the management of DLCL patients.