NK-cells, with their intrinsic ability to recognize and kill tumor cells, represent an interesting tool for immunotherapy. Although infusions of activated NK cells are promising immunotherapy that are safe and well tolerated, the modification of NK-cells with chimeric antigen receptors (CAR) could dramatically improve their functions. The aim of this project was to develop an efficient transduction technique and produce NK cells expressing CARs. Methods. Freshly isolated NK (FI-NK) and NK obtained from the NK-cell Activation and Expansion System (NKAES) were transduced with lentiviral vectors pseudotyped with different envelope glycoproteins. Then, NK-cells were re-expanded using the NKAES system for 14-21 days. Viral receptors expression was evaluated by RT-PCR. The effect of CAR expression was tested with cytotoxicity-assay against a NK-resistant pre-B-ALL leukemia cell line. Results. VSV-G-LVs and MV-LVs resulted in poor NKAES transduction rate (16% and 14%, respectively) while RD114-LVs performed better (38%). The use of BaEV-LVs outperformed them all with a mean transduction rate of 83% in NKAES (p60%). Transgene expression was sustained for at least 21 days. The expression of both BAEV receptor (ASCT1 and ASCT2) could explain the transduction efficacy with BaEV. The transduction with a third generation anti-CD22 CAR (44%) allowed very efficient killing of pre-B-ALL cells. A dual CAR-expressing vector was also tested and could help prevent tumor evasion. Conclusions. This BAEV-LVs will likely be a major tool for the development of NK-based immunotherapy and for the study of NK-cell biology.