The objective of this study was to determine the relationship of national policy and internal migration with the aim to provide some useful determinants in developing migration policies in Tanzania. The study used the multinomial logistic regression model to examine the internal migration factors which are very important in developing migration policies. Secondary data extracted from the National Bureau of Statistics was used for analysis. The study found out that gender, wage differentials, level of education, marital status and age are significant factors in developing migration policy in Tanzania. The study also revealed that more single male with less education make more movements than female. The study suggests that the government and policy makers to review some laws and regulations governing migration. In addition, it suggests that before imposing any restrictive policy, the government authorities are recommended to develop policies that reflect opportunities available in the country with the aim to reduce the negative effects of migration