Since parents and their involvement and attitude have a crucial role in children's achievement in learning English, the present study is to explore and evaluate the impact of Iranian parents' involvement in and attitude toward their children's foreign language programs for learning English. In other words, the effectiveness of their high level of involvement and strength of attitude will be evaluated. Besides, this study is to explore whether some factors such as parents' gender, knowledge of English, income, and educational background are related in the parents' involvement and attitude or not. To this end, first of all, a reliable questionnaire, checked through a pilot study, was distributed among 140 parents to find out the level of their involvement in and attitude toward the programs. Based on the normal curve and the Z score, the parents were divided into two groups, one with a higher level of involvement and more positive attitude and the other with a lower level of involvement and less positive attitude. By using a standard final achievement test of the course book among 70 primary school student in third grade and Independent T-test analysis, the impact of parents' involvement and attitude were checked. As the results revealed those parents who have high level of involvement in and positive attitude toward their children's English language programs made their children's higher level of achievement in the language program. Besides, the further outcomes showed that there are significant differences between the parents' knowledge of English, income, and educational background and their level of involvement and attitude. The aforementioned factors affect children's achievement test scores as well.