THIS STUDY was conducted to determine the phytochemical constituents and in vitro antimicrobialactivity of Abutilonn pannosum (Forst.f.) Schlecht, locally known as ‘ragged mallow, leaf extracts growing wildly in Al-Baha region, Saudi Arabia. The plant leaves were collected, air-dried, macerated, and then extracted with ethanol, chloroform and hot water. The phytochemical constituents and antimicrobial activity against Gram-positive bacteria (Staphylococcus aureus, Bacillus cereus),Gram-negative bacteria (Escherichia coli, Pseudomonas aeruginosa), and the yeast fungus Candida albicans were determined. Results showed that the extracts had saponins, coumarin, alkaloids, tannins, flavonoids, and steroids. GC/MS analysis of ethanol extract revealed 32 compounds, the most important of which were 9-Octadecenoic acid (Z)-, methyl ester, and methyl 10-trans,12-cis-octadecadienoate, while chloroform extract revealed 36 bioactive compounds, the most important of which was phytol, and aqueous extract revealed 43 bioactive compounds, the most important of which was benzyldiethyl (2,6-xylylcarbamoylmethyl) ammonium benzoate. Ethanol extract's antimicrobial activity increased with concentration, from inactive at 25-50mg/mL to moderately active at 100-200mg/mL to active at 300mg/mL. At all concentrations, the activity of chloroform extract was slightly higher, ranging from moderately active to active. The chloroform extract was most effective against all microorganisms tested compared to ethanol and water extracts. This plant can be useful as antimicrobial agent against pathogenic microorganisms, which may be used in food and pharmaceutical industry.