We thus observed the environment of alpha Cen B using the Nasmyth Adaptive Optics System (NAOS) of the Very Large Telescope (VLT), coupled to the CONICA infrared camera. The combination of these two devices is abbreviated as NACO. The first series of observations were obtained between February 18 and April 10, 2004. We repeated the same observations one year later in order to identify the proper-motion companions, using the Ks filter only because all the sources identified in the J and H bands were also detected in Ks. One image of the southern field was obtained in July 2004, but due to operational constraints, the remaining observations were conducted in February-March 2005. (1 data file).