Introduction: In 1935 Stein & Leventhal described seven women presenting with oligomenorrhea combined with the presence of bilateral polycystic ovaries (PCO) established during surgery. The progress in defining the role for leptin in human obesity may be shadowed only by the even faster rise in our awareness of the role of leptin in reproduction. Leptin appears to be the missing link between fat and fertility. When controlled for body weight, no difference is seen between women with and without PCO, however leptin is still involved, and as insulin sensitizing agents may decrease leptin gene transcription.  Leptin stimulates all levels of the reproductive axis, i.e., hypothalamus, pituitary and ovary. The study was conducted on 40 patients classified in to two groups Group (1):  20 PCOS female patients with different body mass indices, Group (2):   20 Non PCOS control female patients healthy with normal cycles and matched BMI. Full history, general and anthropometrics data (age, age of menarche, BMI, duration of infertility, W/H ratio and parity) were recorded also fasting venous blood sample were collected dry tube and glucose level was measured then blood was left till clotted then centrifuged and stored frozen -20 c till the assay analysis time. The aim of this work was to find the association between fasting serum leptin level in women with polycystic ovarian syndrome in relation to their anthropometrics profile and fasting serum insulin. The results of the study showed that In PCOS cases group statistically significant positive correlation (p=<0.05) was found between leptin versus BMI (r = 0.30) and duration of infertility (r= 0.31) among the studied cases by using correlation co-efficient test, while there was no statistically significant correlation found between leptin and anthropometric and  general data (age, age of menarche, W/H ratio and parity). Statistically significant positive correlation was found between leptin and glucose (r=0.38, p <0.05), leptin and LH (r = 0.40, p <0.05) but negative correlation between leptin and insulin (r = -0.42, p <0.05). The ROC curve of fasting serum leptin the area under curve was 75% and the best cut of value for leptin was 14ng /ml with specificity (85%), sensitivity (55%) and accuracy was 70%. In conclusion, PCOS screening test using serum leptin can be used as good negative screening test but not be used alone as good positive. It has a positively correlated to BMI, duration of infertility, glucose and LH. While, inversed correlated to insulin. No statistically significant correlation was found with other general and anthropometrics data, testosterone and FSH.