We investigated the chemistry of a maroon-colored calcareous sponge identified as Leucetta microraphis from Ahnd Atoll, Pohnpei. Antimicrobial screening of its crude methanolic extract revealed mild activity against Bacillus subtilis. Bioassay-guided fractionation using Sephadex LH-20, TSK 40s, and reversed-phase HPLC resulted in the isolation of two active constituents, leucettamols A (4) and B (5). Leucettamol A (C₃₀H₅₂N₂O₂) is an optically inactive pale yellow oil with six cis disubstituted olefinic bonds, two threo-2-amino-3-hydroxy end groups, and is racemic. Leucettamol B (C₃₀H₅₂N₂O₃), also optically inactive, contains one more secondary alcohol than 4, derived from oxidation of the 8,9 double bond of 4 with rearrangement to a 9,10(E) double bond. Both compounds showed mild activity against B. subtilis and very weak cytotoxicity in the SOS chromotest bioassay.