The study was carried out to find out the Influence of Indigenous Language on Advertising Campaign using MTN and GLO telecommunication firms as a case study . In carrying out this study, the researcher used survey research method coupled with questionnaire as the measuring instrument. From the findings, it is established that language is one of the powerful tools in conveying advert messages to the targeted audience. Also, advertising in indigenous language has great impact on the targeted public rather than advert in another language because people tend to understand their native language better and that is both the MTN and GLO used indigenous language in advert campaign regularly. They advertised in indigenous language to enhance understanding, to direct advert message to a particular native, and to let the people feel very important, as a result of this, indigenous language catches people’s attention in advertisement than in English language and pidgin language as it has persuading force on customers. It is recommended that to improve and enhance the use of language particularly indigenous language on the practice of advertising campaign only registered word and expressions should be used while less proverbs and idiomatic expression should be adopted in order to make the message understandable especially as this generation are not familiar with big idiomatic expression, proverb e.t.c . Similarly, because of the potential of audio and visual as both appeals to the illiterates, radio and television should be used regularly to present advert campaign in indigenous language to enhance understanding.