BACKGROUND: Infertility affects 9% of couples of whom 70% suffer from primary infertility and 30% secondary infertility.Upto two third of cases of tubal factor infertility may be attributable to C. trachomatis infection. The present study was done to study the prevalence of serum IgG Chlamydial antibodies in infertile patients METHODOLOGY: A prospective analytical study was done on 70 infertile women in the Department of Obstetrics and Gynaecology,SRN Hospital,Prayagraj, UP, India over a period of one year (October 2018 – September 2019). RESULTS: Prevalence of serum chlamydia in the studied population was 15.71%.Majority of cases were between 21–29 years, 41.43% patients belonged to lower socio economic status, 60% were from rural habitat and 54.55% were illiterate. CONCLUSION: It was concluded from the study that Chlamydia trachomatis serology is a non–invasive and cost–effective test for screening tubal factor infertility.