Natural products used to treat cancer, or as leads for the development of preventive and co-adjuvant treatment strategies, are still a current approach. We studied the effect of essential oils from the medicinal plant Lippia alba on tumor cell lines and observed that geraniol-rich citral chemotype was the most effective, especially for breast and gastric carcinoma. Two main components of these essential oils, geraniol and limonene, were tested on gastric cancer cells, evidencing that geraniol was significantly more effective inducing cytotoxicity. The activity of geraniol on AGS cells was partially due to growth inhibition and we observed that some metastatic gastric cancer cells were also sensitive to this compound. The effect of geraniol on growth inhibition was not recovered by the addition of mevalonolactone, suggesting independence of isoprenylation. A partial inhibitory effect of geraniol was also observed on AGS migration, making it potentially effective to control invasive tumor behavior.