Helicobacter pylori infection affects approximately half of world’s population, is acquired in infancy and has been associated with the development of chronic gastritis, peptic ulcers and stomach cancer in adulthood. The usual treatment that includes two or three antibiotics has led to problems of bacterial resistance, decreased effectiveness, price and safety; showing the need to develop alternative therapies. The Public Health Research Group of the University of Narino (Pasto, Colombia) found that essential oils of Rosmarinus officinalis (L.) and Ruta graveolens (L.) have anti-H. pylori activity in vitro; however, their innocuousness for human consumption was not examined. This study evaluated the cytotoxicity of both oils in human lymphocytes maintained in culture and their mutagenicity by the Ames test with the Salmonella typhimurium strain TA-100. The essential oil of R. officinalis did not present cytotoxic or mutagenic effects in any concentration compared to controls. Pure concentrate of the R. graveolens essential oil was cytotoxic (cell viability 40% lower); however, in dilutions of 10-1 to 10-5, this oil was shown to be safe in both assay systems. These results show that both extracts are promissory for human consumption and in the future, could be considered as an option for complimentary treatment for H. pylori.