Three new diarylpropanes (1-3), a new arylpropyl quinone (4), and the known 1-(2-hydroxy-4-methoxyphenyl)-3-(4-hydroxy-3-methoxyphenyl)propane (5) were isolated from a methanol extract of stems of Combretum griffithii. Their structures were elucidated by spectroscopic methods. Compounds 1, 2, 4, and 5 showed cytotoxicity against one or more cancer cell lines (KB, MCF7, and NCI-H187), and compound 5 exhibited activity against Mycobacterium tuberculosis (MIC 3.13 μg/mL).