Nine new gentisyl alcohol derivatives, namely, the trimeric terrestrol A (8), dimeric terrestrols B-H (1-7), and a monomeric derivative (12), together with four known analogues (9-11, 13) were isolated from the marine-derived fungus Penicillium terrestre. The structures of the new compounds were elucidated by spectroscopic methods including one- and two-dimensional NMR as well as low- and high-resolution mass spectrometric analysis. These new compounds (1-8, 12) showed cytotoxic effects on HL-60, MOLT-4, BEL-7402, and A-549 cell lines with IC50 values in the range 5-65 microM. Compound 6 also showed moderate inhibitory activity against protein tyrosine kinases (Src and KDR). Furthermore, all new compounds exhibited moderate radical scavenging activity against DPPH with IC50 values in the range 2.6-8.5 microM.