"Radio advertising in Argentina has been adapted to the changing needs of radio. This paper aims to describe and analyze the advertisement formats used in the four leading prime time programs in Argentina. The methodology is a content analysis that is applied to a sample of four programs each one with duration of four hours (ranging from 9 AM to 1 PM, Monday through Friday) for two weeks in October 2010. Therefore, the sample amounts to 160 hours of programming, 40 for each program. Sponsorships are least used, while the advertising segments are prevalent in all programs. The advertising segments are very different in length for the AM vs. FM. The “mention” has becomed increasingly common in prime time. The speaker´s role is essential to the "selling” of products or services and his function becomes more important when programs incorporate dialogue sections to include brand mentions with time for humorous banter. The terms of prime time advertising on Argentinean radio have changed in recent years in order to adapt to the current needs of radio: programming criteria, use of ss, variety of content and voices and interaction with the listener." (Abstract)