A new 2H-tetrahydropyran derivative, 6-epi-goniothalesdiol A (1), together with nine known styryllactones (2–10) and five known aristolactams (11–15) were isolated from the bark of Goniothalamus elegants Ast. The structures were elucidated by spectroscopic methods. The isolated compounds were evaluated for their cytotoxicity toward the KB, MCF7 and NCI-H187 cell lines as well as antimalarial and antimycobacterial activities. Compounds 4 and 10 showed strong activity against all three human cancer cell lines with IC 50 values in the range of 0.538 to 4.25μg/ml, while compounds 2, 4, 10 and 14 showed potent cytotoxicity against NCI-H187 with IC 50 values in the range of 0.072 to 2.17μg/ml. In addition, compounds 4, 6, 7, 9, 10 and 13 showed strong antiplasmodial activity with IC 50 in the range of 2.28 to 5.89μg/ml.