A Dissertation Submitted in Partial Fulfilment of the Requirements for the Degree of Master’s in Life Sciences of the Nelson Mandela African Institution of Science and TechnologyVarieties of plants, including Cymbopogon citratus, are traditionally used in controlling hyperglycemia by either stimulating insulin secretion, inhibition α- Glucosidase or α-amylase activity. Cymbopogon citratus leaves were studied in this study to elucidate the effects of actively fractionated fraction from crude extract in lowering blood glucose in diabetic mice. The C. citratus powder were extracted by cold maceration using ethanol. Fractionation was done by Vacuum Liquid Chromatography (VLC). Oral glucose tolerance test (OGTT) was performed for both crude extract and fractions. Diabetes was induced in mice by intraperitoneal injection of freshly prepared alloxan monohydrate (170 mg/kilogram/body weight) which interferes with insulin secretion. The mice were treated with ethyl acetate fraction once daily at 400 mg/kilogram body weight dose for the period of 20 days. Fasting blood glucose (FBG) and weight were then recorded from mice in days 1, 5, 10, 15 and 20. Acute toxicity done by Lorke’s method. The difference between means of two population groups was considered significant at p<0.05 by One-way ANOVA. Results were expressed as mean ± SD. Significance hypoglycemic activity was shown by ethyl acetate. No mortality was observed at 5000 mg/kilogram body weight dose but sleeping and tremor were observed at a 1000 - 5000 mg/kilogram body weight. Phytochemical screening of ethyl acetate fraction showed presence of alkaloids, saponins, antraquinone, phenol and tannins. Good hypoglycemic effect and safety results from ethyl acetate fraction suggest that C. citratus extracts are against insulin-dependent hyperglycemia. Isolation and testing of active ingredients from the C. citratus extract are thus warranted.