The purpose of this study was to examine Iranian EFL teachers' attitudes towards lesson plan based on their gender. The research is a quantitative study in which the data is obtained to get a great understanding on the relationship between lesson plan of Iranian English as Foreign Language (EFL) teachers and teachers' gender. The population included 93 teachers in Eyvan and Ilam, Iran high schools and institutes. Participants in this study answered a Modified Questionnaire, adopted from Ramaila et al (2014). Independent sample t-test was computed to determine the difference between teachers' attitudes towards lesson plan and their gender. Through statistically analysis it was found that, the female teachers were more interested in use of lesson plan than the male teachers. This paper recommends that more seminars workshops and in-service courses be organized for all science teachers to help train and boost their attitudes on the significance of lesson plans in teaching/learning of English in schools.