Argemone mexicana L is one of the medicinal plants used traditionally for its curative properties. The observed activities could be due to the presence of phytochemicals present in the plant. The purpose of this study is to carry out the quantitative and qualitative analysis of the constituent phytochemicals of Ethanol and aqueous extracts of the leaves of the plant as well as determine its microbial activities against some selected bacteria and fungi. Results showed that alkaloid is present in both ethanol and aqueous samples. Terpenoid is present in aqueous sample but abundantly present in ethanol sample. Phenol is present in aqueous sample but abundantly present in ethanol sample. Steroids are present in ethanol sample but absent in aqueous sample.  While anthraquinones are present in the aqueous sample, the quantity is not much compared with what was obtained from the ethanol sample. Cardiac glycoside is absent in both samples but flavonoid is present in both samples. It was observed that saponins and tannins were abundantly present in the ethanol extract but not much in the aqueous extract. The results of the quantitative analysis showed that for aqueous extract, alkaloid is 9.5 % w/w, flavonoid (0.36% w/w), saponin (4.7%w/w), tannin (0.1% w/w) terpenoid (0.45 w/w) and total phenol (0.65% w/w). For ethanol extract it was alkaloid (9.7 %w/w), flavonoid (1.59% w/w), saponin (6.3% w/w), tannin (1.06% w/w), terpenoid (0.75% w/w) and total phenol (0.74% w/w). The MIC and MBC measured in µg/mL of ethanol and aqueous samples against Staphylococcus aureus were (3.125:6.25) and (12.5:12.5) respectively. Bacillus subtilis (25:25) and (25;25), Escherichia coil (6.25: 25) and (12.5: 50), Salmonella typhi (>50: 25) and (6.25: 12.5), Klebsiella pneumonia (12.5:25) and (1.56:6.25), Pseudomonas aeruginosal (50:50) and (3.125:6.25), Tricophytum rubrum (25:25) and (3.125: 3.125), Candida albican (25:25) and (6.25:12.5) respectively. All Our study showed that the plant has high potential as an antifungal and antibacterial agent.