Aim: to determine the aetiologies for Primary Infertility among women of reproductive age group. Methods: A comparative observational study was conducted in the Department of obstetrics and gynaecology, VIMS, Pawapuri, Nalanda, Bihar, India, India for 2 years, Total of 1100 women could be interviewed. A type-specific ELISA test was used to detect HSV-2 IgG antibodies. Vaginal swabs were also cultured, using organism specific kits, for Trichomonas vaginalis, Candida species, and Neisseria gonorrhoeae, according to manufacturer’s instructions. All diagnostic tests were carried out in the microbiology laboratories. Results: Prevalence of primary infertility in our study was 100 (9.09%) and prevalence was significantly more in the Upper middle class (43%) and among Hindus (52%). Mean age at menarche (13.97yrs), Mean age at first sexual activity (20.05) and mean number of unprotected sexual acts in previous three months (37.78) was significantly higher in women with primary infertility while mean years of marriage (8.55) significantly higher in fertile women. Overall, lower number of infertile women reported to have abnormal vaginal discharge, burning urination and vaginal itching. The prevalence of genital ulcer was significantly more in infertile group (p 0.0001). Women with genital ulcer were at increased odds of infertility (OR: 2.52; 95% CI: 1.57–3.80) compared to women without genital ulcer. Abnormal vaginal discharge was significantly more in women in the fertile group (p 0.0001). Women with abnormal vaginal discharge were at decreased odds of infertility (OR: 0.39; 95% CI: 0.26 – 0.60) compared to women without abnormal discharge. Conclusion: Primary infertility is increasing and is emerging as a new public health problem which needs immediate attention be- fore it goes out of hand.