The bryozoan cheilostomatous species Chartella (Terminoflustra) membranaceatruncata was investigated for the presence of antimicrobial agents. Antimicrobial activity against fungi, Gram positive and Gram negative bacteria was detected in an acidic extract of the bryozoan colonies. The strongest antimicrobial activity was seen against the fungal strains Candida albicans and Saccharomyces cereviseae. A combination of electrophoresis and HPLC fractionation methods was used to isolate a fungicidal substance with MW 396.83 Da. The molecular structure was determined using nuclear magnetic resonance analysis and identified as 2-(2,5,8-tribromo-1H-indol-3-yl)ethanamine). Similar tribrominated compounds have been described previously in the ctenostomatous bryozoan species Zoobotryon and Amathia.