Introduction: Among the threats that change the family structure are early marriage and the phenomenon of child marriage. The World Health Organization considers early marriage as the marriage under the age of eighteen. Due to the importance of this issue, this study aimed to examine the causes and consequences of early marriage and the occurrence of child marriage in female students of Yazd province.
 Method: This qualitative study was conducted based on the grounded theory. The research environment included all divorced female high school students in the academic year of 209-2010 in Yazd province. Of the participants and based on theoretical, targeted, and snowball sampling, in-depth semi-structural interviews were conducted on them and until the theoretical saturation was reached, 11 people were finally selected.
 Result: The data were analyzed using Strauss and Corbin method with three steps of open, axial, and selective coding. Finally, from open coding 550 initial concepts, from axial coding 27 categories, and finally 8 main categories were extracted. The main categories included lack of communication, irresponsibility, lack of marital intimacy, lack of socio-moral maturity, psychological turmoil, risks and consequences of divorce, academic challenges and interpersonal problems.
 Conclusion: The results showed that early marriage has many disadvantages, including divorce. Communication problems were at the top of students' problems at the time of marriage. This lack of communication leads to problems, such as marital intimacy, interference of others, educational problems, and sometimes infidelity.