Macroalgae were collected in the marine environment in order to evaluate the efficiency of organic extracts in controlling papaya (Colletotrichum gloeosporioides (Penz.) Penz. et Sacc.). Eight species were identified, four belonging to Chlorophyta phylum Caulerpa cupressoides (West) C. Agardh, Caulerpa racemosa (Forsskal) J. Agardh, Codium isthmocladum Vickers, Halimeda cuneata (K. Hering) and four belonging to Rhodophyta phylum Hypnea musciformis (Wulfen) J.V. Lamouroux, Laurencia dendroidea (Hudson), Montagne, Ochtodes secundiramea (Montagne) M.A. Howe, Pterocladiella capillacea (Santelices & Hommersand). The fresh algae were exposed to a dichloromethane and methanol mix (4:1) in order to obtain the extracts, which were concentrated by evaporation. The extracts were prepared at the concentrations of 1 ppm and 2 ppm, directly in the PDA medium, and tested in vitro, evaluating the influence on the Micelial Growth Velocity Index (MGVI). The H. musciformis, L. dendroidea and O. secundiramea extracts showed marked action on the vegetative growth of C. gloeosporioides. The O. secundiramea extract at the concentrations of 1 ppm and 2 ppm reduced de MGVI in 91% and 100%, respectively, compared to the control.