polycystic ovary syndrome is the commonest cause of an ovulatory infertility, and is the most 
common endocrine abnormality in reproductive age women.IN these study we try to evaluate the 
efficacy of co-administration of low-dose aspirin and clomiphene citrate on ovulation rates, 
endometrial thickness and clinical pregnancy rates in cases of clomiphene resistant PCOS at Minia 
university hospital over one year. Our study include 81 patient diagnosed with PCOS. Color and 
power Doppler ultrasonography was performed before and after treatment. Induction of ovulation 
done by clomiphene citrate 150 mg tablets and accompanied by a daily oral low dose of aspirin 
(75mg). Folliculometry, Endometrial thickness and appearance were assessed before and after 
treatment. We found that Dominant follicles of the studied group , Endometrial thickness and 
appearance and Clinical pregnancy rate were highly statistically significant differences between 
before and after treatment. Our clinical trial showed that low-dose aspirin administration results in 
high pregnancy rate. LDA seems to be a useful, effective, cheap and safe treatment in patients who 
undergo ovulation induction.