Introduction: Aspartame (ASP) is a synthetic sweetener low-caloric consumed worldwide by 200 million subjects. Recently, drawbacks of aspartame have been detected on several body tissues including the reproductive system and blood parameters. Aim: The present work aimed to detect effects of long-term intake of aspartame at two doses over blood picture and ovaries in adult female albino rats. Material and Methods: In the present work, 40 adult female albino rats divided into 4 groups, two control groups (without any treatment) and another two groups receiving aspartame (50, and 100mg/kg/b.wt) using oral gavage for 91days. First, rats were euthanized, then, blood samples and ovarian tissues, collected for histomorphological studies. ANOVA and post- hoc test employed to compare group means under study. Results: ASP (50 & 100 mg/kg/b.wt) had resulted in a considerable decrease in serum estrogen and significant changes in blood picture parameters: decrease in RBC count, MCV, MCH and a significant decrease in WBC count than in control groups. Histopathological results were indicative of significant ovarian tissue affection in form of decreased ovarian follicles, less mature graafian follicles, most cells showed vacuolations, some showed atrophic changes. Ovarian stroma revealed a large number of noticeably dilated and congested blood vessels. There were hemorrhagic and necrotic foci with chronic inflammatory infiltrate and fibrosis. An increase in surrounding adipose tissue was detected. A notable drop in serum estrogen detected in aspartame groups in contrast to control groups. Conclusion: Aspartame has a negative effect (50 &100mg/kg/b.wt/day doses) on blood components and a considerable histopathological deterioration of ovarian structures. Recommendations: Further studies needed to detect whether aspartame effects were reversible or not.