Infertility is defined as the failure to conceive after one year of unprotected intercourse. It is divided into primary and secondary types. It is extremely important to regard infertility as a "two-patient disorder ". This study focused on the hormonal and trace element factors affecting infertility. One hundred and twenty women, age ranged between 22-46 years (duration'of infertility ranged from 3-25 years) who underwent In Vitro and Embryo Transfer program at the IVF-ET (Test-Tube Baby) center in in Al-Elwya Women Teaching Hospital during the period April-October 1999 were enrolled in this study. They were classified into four groups (ovulatory, tubal, unexplained and control group [male factor]). A special questionnaire form was filled for each patient that includes, the history, clinical investigations, examinations done for the women and her husband. They were treated with short-stimulation regime for ovulation induction as controlled ovarian hyperstimulation. Follow up by measuring estrogen and transvaginal ultrasound. Estimation of steroid hormones (estrogen and progesterone) and trace elements (zinc, copper, slenium, cadmium, nickel, cobalt and lead) in serum and follicular fluid at the day of ova pickup. The results of this study revealed a difference in hormonal and trace elements measured between serum and follicular fluid concentrations and also difference was noted according to the cause of infertilityThese results are discussed carefully in this study and were shown that there is a conspicuous relation between different trace elements themselves and between trace elements and the hormones measured which imply a specific mechanism(s) that affects fertility. This study revealed the role of trace elements on the hormones and their relationship with pregnancy rate and causes that lead to infertility.