Due to the importance of creativity in teaching and learning, this study was conducted to study teachers' creativity and its relationship with their teaching's effectiveness. Another aim of this study was to measure the creativity among men and women teachers at English institutions in Iran. A sample of 325 EFL Iranians' teachers was randomly chosen and was rated on the ELT-CS and teaching effectiveness scale. With this aim, validated and reliable scales of assessing creativity (ELT-CS) of EFL teachers teaching effectiveness scale were used. After gathering the questionnaires, data was analysed by structural equation modelling approach. According to the results, five subscales of creativity have a significant relationship with teaching effectiveness. Also, the results have shown that there is a significant difference between gender and teachers' creativity.