Many biology students are drawn to medically oriented topics. This lab activity engages students with medical interests in botany. I find that students are interested in how plants can have medical applications, for example in pharmaceuticals. Several volatile oils of plants, such as thyme, oregano, tea tree, and black pepper oils, have been found to have antibacterial, antifungal, or antiviral properties. To further their interest in the plant kingdom, teachers can have students test a variety of essential oils for effectiveness as antibiotics. This activity requires only minimal microbiology technique and is appropriate for high school through introductory college biology and botany courses.