This paper presents an empirical investigation to study the effects of advertisement on brand equity. The study has accomplished on two well-known brands in mobile providers in city of Tehran, Iran. The study uses Aaker’s model to examine the effects of advertisement on various factors such as brand awareness, quality perception, brand loyalty and brand associate. The study also investigates the effects of brand awareness, quality perception and brand associate on brand loyalty. The results of our survey have concluded that advertisement could influence on some of the components of brand equity, significantly. For the first case study of this survey, Irancell, advertisement influences on brand awareness, brand quality and brand associate, significantly. In addition, brand awareness and brand loyalty also influence on brand quality and brand equity, positively. For the second case study of this survey, Mobile Telecommunication Company of Iran, the effects of advertisement on brand equity, brand awareness and brand associate have been confirmed. Moreover, brand awareness and brand quality influence on brand loyalty, positively. In addition, brand loyalty influences positively on brand equity.