The present study evaluated the biological activity of 12 marine macroalgae from Ceará State, Brazil. From the collected species 48 extracts (aqueous, dichloromethane, acetone and methanol extracts for each species) were obtained. The activity of extracts were rated at the following bioactivities: lethality in brine shrimp nauplii, inhibition of the development of sea urchin eggs, hemolytic activity on mice ery...