Background and objective: Infertility is a global health issue, affecting approximately 8- 10% couples worldwide. The 1981 census of India estimated infertility to be in the range of 4-6%. The biological and social factors including stress due to economic status, religious attitudes, age at marriage, higher literacy, contraceptive usage and nuclear families play a significant role in lowering fertility. In this background present study was undertaken to find out the prevalence and factors influencing primary and secondary infertility among couples in rural field practice area of Nathnagar. Methods: The present cross sectional study was conducted at Bhagalpur Primary Health Centre area, which is the rural field practice area of Department of Community Medicine, JLNMCH Bhagalpur. from Feb 2020 To Feb 2021 for a period of one year. Complete enumeration of the entire Nathnagar Primary Health Centre area was done to identify couples with either primary or secondary infertility. Data was collected using predesigned pretested structured proforma by interview technique. Results: Prevalence of infertility in the study area was 8.1% among which prevalence of primary infertility was 4.5% and secondary infertility was 3.6%. The most common cause of infertility among females was pelvic inflammatory disease followed by polycystic ovarian disease and among males it was oligospermia. The bio social factors found significantly associated with primary infertility were family history of infertility, hypothyroidism, abnormal vaginal discharge, irregular menstrual cycles among females and among males hypothyroidism , family history of infertility, alcohol and tobacco consumption. Conclusion: This study has yielded important information regarding the prevalence and risk factors influencing infertility. Efforts to raise awareness in the population about the causes of infertility are needed.