Introduction: To determine fertility influential factors, demographical researchers study influential economical, social and cultural elements. The aim of this article is to apply Poisson regression model to investigate influential factors on children ever born, one of the fertility determinant indices, of migrant women to Tehran according to 2011 Population and Housing Census.
 
Materials & Methods: From 2011 Population and Housing Census data, 33420 ever married migrant women to Tehran were selected. Poisson regression model of these women's children ever born according to predictors of age, educational level, job status, internet use, and migration cause has been fitted by SPSS 22.
 
Findings: All of the predictors (age, P-value< 0.001, educational level, P-value< 0.001, job status, P-value< 0.001, internet use, P-value< 0.001, and migration cause, following family, P-value< 0.028)  and interaction of women's age and women's migration cause (P-value< 0.001) had significance effects on children ever born.
 
Discussion & Conclusions: The results of fitted Poisson regression showed that women in older age groups with lower educational level, unemployed, and those who didn’t use internet and their cause of the migration was following family had greater mean of children ever born. According to the results, it can be concluded that the possibility of increasing children ever born of women in younger ages, with higher education and employed could be existed by applying correct fertility policies.