Objective: To evaluate incidence of microbial growth from the tip of the embryo transfer catheter after embryo transfer in relation to clinical pregnancy rate following in-vitro fertilization and embryo transfer. Method: This study was performed prospectively at the time of transcervical embryo transfer following conventional in-vitro fertilization and intracytoplasmic sperm injection procedures. Sixty three patients were enrolled in this study. Microbiological cultures were performed on endocervical swabs and embryo transfer catheter tips. Results: Positive microbial growths were observed from endocervical swabs in 45 (71.4%) women and from catheter tips in 30 (47.6%) women. There was no statistically significant difference seen in the mean number of oocytes fertilized or number and grade of embryos transferred between the group of patients without growth and the group of patients with positive microbial growth from catheter tips. The clinical pregnancy rate were 30.3% in the group of patients without growth and 13.3% in the group with positive microbial growth from catheter tips. This difference in clinical pregnancy rates was statistically significant. Conclusion: Our finding is that microbial contamination at embryo transfer may influence implantation rates. The major questions arising from our finding are whether eradication of endocervical micro-organisms is possible and whether their eradication will improve implantation rates.