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The fruits of <i>Amomun tsao-ko</i> (Chinese black cardamom; Zingiberaceae) contain an abundance of essential oils, which have previously demonstrated significant antimicrobial activity. In our preliminary search for natural anti-tuberculosis agents, an acetone extract of <i>A</i>. <i>tsao</i>-<i>ko</i> (AAE) exhibited strong antibacterial activity against <i>Mycobacterium tuberculosis</i> H37Rv. Therefore, the aim of this study was to find the principal compounds in an AAE against <i>M</i>. <i>tuberculosis</i>. Nine aliphatic compounds (<b>1</b>–<b>9</b>) including a new compound (<b>1</b>, tsaokol B) and a new natural unsaturated aliphatic diester (<b>6</b>), together with three acyclic terpenoids (<b>10</b>–<b>12</b>), were isolated from an AAE by repetitive chromatography. The structures of the isolates were determined by spectroscopic data analysis. All isolates were evaluated for activity against <i>M</i>. <i>tuberculosis</i> H37Rv. Isolated compounds <b>1</b>–<b>6</b>, and <b>11</b> had MICs ranging from 0.6–89 µg/mL. In contrast, compounds <b>7</b> to <b>10</b>, and <b>12</b> had MICs that were >100 µg/mL. Tsaokol A (<b>3</b>) was the most active compound with MICs of 0.6 µg/mL and 1.4 µg/mL, respectively, against replicating and nonreplicating <i>M</i>. <i>tuberculosis</i>. These results are the first to illustrate the potency of tsaokol A (<b>3</b>) as a natural drug candidate with good selectivity for treating tuberculosis.