OBJECTIVE To determine the frequency of occurrence of Mycoplasma genitalium infection in the peritoneal fluid of infertile women as compared to fertile women. METHODS We have selected 162 infertile women aged 22-40 years as study subject and 162 women posted for elective caesarean section, were taken as control. Peritoneal fluid of the infertile women and control samples was obtained by suction during diagnostic laparoscopy and M. genitalium infection was diagnosed by PCR method. RESULTS The genetic material of M. genitalium was detected in the peritoneal fluid of 10 subjects in the infertile group and in 1 from the control group. High prevalence was found in cases with unexplained (13.3%) and primary infertility (6.7%) in comparison to explained (4.5) and secondary infertility (4.5%). Consistent relationship was reported between past obstetric history and presence of M. genitalium infection in infertile subjects. M. genitalium infection was two times more common in women with cervicitis (8.6%) and with blocked fallopian tubes (8.4%). Out of the 101 cases with normal looking uterus, 7 had M. genitalium infection, while 3 out of 61 cases with a congested uterus had infection. The fallopian tubes appeared normal in about 53% cases whereas, inflammation, hydrosalpinx, peritubular adhesions and endometriotic patches were noted in 11.7%, 4.3%, 19.7% and 11.1% of cases respectively. CONCLUSIONS Present study shows association between M. genitalium infection and infertility. We suggest routine screening and early treatment of this pathogen because prolonged inflammation of upper genital tract sites may lead to significant reproductive morbidity and infertility.