Learning English in Iran is quite popular, yet not all are successful at this task. To shed light on this dilemma and its root causes, the roles of socio-economic status and motivational selves among Iranian English learners are explored in this research. A total of 892 participants in this research sampled through proportional sampling from among high school and university students. Measures used are questionnaires on motivational selves and socio-economic status, and a standard test in English language skills. Analysis of the collected data shows that the ideal and ought-to selves, next to attitude towards learning English, explain the variance in English language skills. Furthermore, it is the attitude in the learning environment, rather than other people’s expectation through ought-to self, that informs motivation. Also the SES mediates the effect of the ideal self on second language learning, i.e. those with high SES who have a better ideal self, learn language skills better than those with low SES because the former do not benefit from a high ideal self.