Investigation of the aerial parts of the Egyptian medicinal plant Ammi majus L. led to isolation of new coumarin, 6-hydroxy-7-methoxy-4 methyl coumarin (2) and 6-hydroxy-7-methoxy coumarin (3); this is the first time they have been isolated from this plant. The structures of the compounds (2 &3) were elucidated by spectroscopic data interpretation and showed anti-inflammatory and anti-viral activity. GRAPHICAL An efficient, one-new coumarin (2) was isolated from the aerial parts of the A. Majus L. was evaluated for their anti-viral and anti-inflammatory activities.