Antibiotic resistance is becoming more and more common among both pathogenic and non-pathogenic bacteria alike. While measures which limit emerging resistance to our current range antibiotics are being adopted, new drugs are still needed. Traditionally marine invertebrates have been an excellent source of bioactive compounds with potential for pharmaceutical applications. Sponges, which are members of the phylum Porifera, represent an especially rich source of novel compounds. This account outlines the reasoning, procedures, results and applications of our study in which crude chemicals were successfully extracted from two unidentified Hexactinellida sponges and screened for bioactivity against six clinically important bacterial species, in addition to four Fungi and one Yeast Species. It is the hope of the author that this book will be found useful by individuals and organizations interested in Natural Product Chemistry and Antibiotic development.