AIMS 1. The study aimed to evaluate presence of sexually transmitted infections in pregnant women and to study its distribution in relation to age, parity, social class, habitat and education. 2. To study symptomatology and signs of different sexually transmitted infections in pregnancy and its adverse effects on maternal and pregnancy outcome. MATERIAL AND METHODS Sexually transmitted infections in Department of Obstetrics and Gynaecology, Gandhi Medical College, Sultania Zanana Hospital, Bhopal, during 15 months' period from August 2010 to October 2011 were studied. The individual records of all sexually transmitted infections occurring during the study period of 15 months were extracted from patient's case notes and hospital record registers. RESULTS In year August 2010 to October 2011, this study is done on 500 pregnant women in all trimesters of pregnancy, out of which 195 (39%) women were found positive for sexually transmitted infections and among this positive women, maximum i. e. 102 (52.3%) women were in age group 20-24 years followed by 61 (31.2%) women in 25-29 years of age group. Among positive found women 131 (67.17%) women were urban dwellers. The highest number of sexually transmitted infections occurred among multigravida 107 (54.87%). Most of the women who were having infection were illiterate 97 (49.74%), belonged to low socioeconomic class 147 (75.47%), not using any form of contraception 142 (78.82%), has poor genital hygiene 153 (78.5%). And out of 195 infected women, maximum 155 (79.48%) were having one or another symptoms and most common complaint with which they present is discharge per vaginum 54 (27.6%) followed by discharge+itching 47 (24.1%). Out of 195 women found positive for STI, 21 (10.76%) were having viral infection, 119 (61.03%) were having non-viral (Bacterial/fungal or parasitic) STI and 55 (28.2%) had mixed infections and among pregnancies with STI's 98 (54.7%) had adverse pregnancy outcome. CONCLUSIONS This study has demonstrated that frequency of sexually transmitted infections is unacceptably high and this continues to have an impact on pregnancy outcome. Integration of antenatal screening services for these infections and treatment during antenatal care should be prioritized.