English is so widely spoken that it has often been referred to as a world language, the lingua franca of the modern era for access to business, the media, science and technology. The potential forces English could have on the world languages are so overwhelming that different researches have been sought out so as to predict the effects thereof.As for this, the present study, which is based on Baker’s (1992) and Oakes’s (2001) theoretical frameworks, aimed at investigating the attitudes of Persian speakers towards Persian, as their national language, and English, as an international language. The questions addressed in this paper are as follows: 
- What is the attitude of Persian speakers towards English as an international language?
- What is the attitude of Persian speakers toward Persian as their national language?
- How is the relationship between the speakers’ attitude towards English and their attitude towards Persian?
The survey was carried out by distributing the devised questionnaire among 820 participants selected randomly from among four different groups of Persian speakers in Tehran.Finally, the findings of the study revealed that the attitude of Persian speakers is positive towards both Persian and English. The findings also pointed out that there is a direct relation between the speakers' attitude towards Persian and English; hence, the more positive the speakers' attitude towards English is, the more positive their attitude towards Persian will be. Conversely, the more negative the speakers' attitude towards English is, the more negatively they will think of Persian.