A species of sea star was collected from the Mediterranean Sea, Alexandria, Egypt. It was identified based on general morphological and anatomical features as Astropectenspinulosus. The antibacterial and antifungal activities were investigated via the standard techniques. Data obtained revealed that the inhibition zones as a factor for antibacterial activity of A. spinulosus ranged between 0 and 18 mm. The highest antibacterial activity was detected against P. aeruginosa (18 mm) for ethanol extract, followed by B. subtlis (14 mm) for methanol extract, then by P. aeruginosa (13 mm) for both ethyl acetate and methanol extract. Different solvent extracts recorded inhibition zones as antifungal activity ranged between 8 to 10 mm. the most suppressed fungus was P. crustosum by acetone and ethanol extracts as80 and 90%, respectively. Weakly, A. terreus was suppressed by ethanol and methanol extracts of A. spinulosus as 10 and 20%, respectively. The suppression was not taken place against other fungi by any solvent extract. Regarding to investigating the efficacy of some commercial antibiotics (mm), data confirmed that the Gram-negative bacteria were more resistant than Gram-positive bacteria. On the other side, the result of GC-MS/MS of crude extract observed the presence of several bioactive constituents, most of which had antimicrobial activities.