<jats:title>Abstract</jats:title><jats:p>Phytochemical investigations of the stems of a specimen of <jats:italic>Alibertia macrophylla</jats:italic> led to the isolation and characterization of the new diterpene <jats:italic>ent</jats:italic>‐kaurane‐2<jats:italic>β</jats:italic>,3<jats:italic>α</jats:italic>,16<jats:italic>α</jats:italic>‐triol (<jats:bold>1</jats:bold>), along with triterpenes <jats:bold>2</jats:bold>–<jats:bold>8</jats:bold>, iridoids <jats:bold>9</jats:bold>–<jats:bold>12</jats:bold>, and phenolic acids <jats:bold>13</jats:bold>–<jats:bold>15</jats:bold>. The structure of <jats:bold>1</jats:bold> was established based on spectroscopic studies (<jats:sup>1</jats:sup>H‐ and <jats:sup>13</jats:sup>C‐NMR, IR, and HR‐ESI‐MS). This is the first report of the isolation of a diterpene from the <jats:italic>Alibertia</jats:italic> genus in Rubiaceae.