BACKGROUND: Infertility rate among Mongolian couples was about 8.7% in 2003. According to researchers in Mongolia, the causes of infertility in male is about 25.6%, in female is about 45.8%, in both couples is 18.8% and unexplained infertility is about 9.8%. Women’s previous disease such as abdominal inflammatory diseases, disorders of pregnancy and surgical diseases of reproductive system can lead to infertility. Infertility has been setting 5th rank on list of human disability as shown as problem about quality of human life. METHODS: We surveyd about secondary infertile women, who has approved by inclusion criteria and determined infertility risks. We designed case-control study. We collected 52 data at “Post partum department” of “First Maternity Hospital” for control group, and 22 data at “Women stationary” of “First Maternity Hospital” for case group (ratio 2:1). Data analyzed by STATA for OR (logistic regression tests) and Microsoft Excel. RESULT: The most common previous disease is pelvic inflammatory disease (OR=2.2) р<0.001 before infertility situation. There was statistical reliability diseases. Including: female reproductive system surgery (OR=2.1), pelvic surgical diseases (OR=1.9) and complication of previous pregnancy (1.2). CONCLUSION: Pelvic inflammatory disease, surgical diseases of female reproductive system, complication of previous pregnancy and pelvic surgical diseases are the risk factors of female secondary infertility.