Curcuma purpurascensBl., belonging to the Zingiberaceae family, is known astemu tisin Yogyakarta, Indonesia. In this study, the hydrodistilled dried ground rhizome oil was investigated for its chemical content and antiproliferative activity against selected human carcinoma cell lines (MCF7, Ca Ski, A549, HT29, and HCT116) and a normal human lung fibroblast cell line (MRC5). Results from GC-MS and GC-FID analysis of the rhizome oil oftemu tisshowed turmerone as the major component, followed by germacrone,ar-turmerone, germacrene-B, and curlone. The rhizome oil oftemu tisexhibited strong cytotoxicity against HT29 cells (IC50value of 4.9 ± 0.4 μg/mL), weak cytotoxicity against A549, Ca Ski, and HCT116 cells (with IC50values of 46.3 ± 0.7, 32.5 ± 1.1, and 35.0 ± 0.3 μg/mL, resp.), and no inhibitory effect against MCF7 cells. It exhibited mild cytotoxicity against a noncancerous human lung fibroblast cell line (MRC5), with an IC50value of 25.2 ± 2.7 μg/mL. This is the first report on the chemical composition of this rhizome’s oil and its selective antiproliferative effect on HT29. The obtained data provided a basis for further investigation of the mode of cell death.