Most of the Indian states have been successful in enrolling more children in school along with substantial increase in primary schools in the recent decades, a very large numbers of students continue to be out of school which is one of the key barriers in fulfilling the constitutional commitment to make elementary education free and universal for all. Understanding why students drop out of school is the key to addressing these major educational problems. Yet identifying the causes of dropping out is extremely difficult to do because, it is influenced by an array of proximal and distal factors related to both the individual and the student and to the family, school, and community settings in which the student lives. This paper studies the reasons of high dropout rates in the Karbi Anglong (KA) District of Assam. Dropping out of children from primary school has become a challenging issue in the education system especially for regions like KA, where right to education has been denied to an alarming number of children because of dropping out. The study also shows the extent to which higher level of school dropouts adversely affect the socio-economic outcomes of a region. There is strong evidence on the influence of different socio-economic factors such as school related, individual related or household related on school dropouts of KA region. Beside the impact of socio-economic factors dropout rate is largely affected by the environmental, geographical barriers like drought, flood, migration etc. It is very pertinent to find the reason for dropouts, not only because human resources are being unused but also dropouts cost the nation money. Dropouts are less likely to find and hold jobs that pay enough to keep them above the poverty level. Higher rates of unemployment and lower earnings cost the nation both lost of productivity and reduced tax income. Dropouts are also more likely to have health problems, engage in criminal activities, and become dependent on families, welfare and other government programes.