At present, most of cochlear implant patients wear only one implant in one ear. While the use of a single implant allows users to understand oral speech in most cases, it seems that they can not localize source of sounds. Indeed, most of our spatial localization abilities are closely related to binaural hearing. The «Centre Romand d’Implants Cochléaires» just started a study aimed to quantify the localization abilities of binaural cochlear implant patients. First experiments allowed to measure and to compare the localization abilities of cochlear implant patients, in monoral versus and binaural listening conditions. These first measurements, conducted for two binaurally implanted subjects, confirmed that localization abilities in monoral conditions were almost zero. Nevertheless, in binaural conditions, the measurements revealed that both subjects could localize source of sounds with a precision of ± 23° in 75% of cases. These results were encouraging as implants were not synchronized and were even of different trademarks.