Two sesquiterpenoids, axisonitrile-1 and axisothiocyanate-1, have been isolated from the sponge AxineUa cannabina. On the basis of chemical find physico-chemical evidence structure 1 is suggested for axisonitrile-1 and structure 2 for axisothiocyanate-1.The only known naturally occurring isonitrile is the antibiotic xanthocillin discovered by Rothe' in cultures of PeniciUium notatum Westling and Penicillium chrysogenum. During our studies on the metabolites of Porifera 2 we isolated a sesquiterpenoid isonitrile, axisonitrile-1, from the marine sponge AxineUa cannabina and describe the assignment of structure 1 to this compound. In addition, we isolated from the same sponge axisothiocyanate-1 (2) and the structure determination proved it to be an isothiocyanate strictly related to 1.