The chemistry of Geranium columbinum and G. lucidum volatiles has been studied here for the first time. The essential oils were obtained by hydrodistillation, analyzed by GC and GC-MS, and screened for their in vitro antibacterial and antifungal activity in a microdilution assay. In total, 172 constituents were identified, accounting for 88.1%-96.7% of the detected GC peak areas. The essential oils consisted mainly of fatty acids and fatty acid-derived compounds (65.0%-86.3%). The major compounds of the essential oils were hexadecanoic acid, hexahydrofarnesyl acetone, and tetracosane. The antimicrobial assay showed a strong activity of the oil from aerial parts of G. columbinum against the pathogenic yeast C. albicans (MIC = 0.437, MBC = 1.75 mg/mL).