Objective: Salivary incubation assays are commonly used in oral malodor studies. Using an in vitro model system, the effect of various natural medicinals (ie, echinacea, propolis, elder, mastic gum, marigold, sage, lavender, thyme, and chamomile) on salivary protein putrefaction and malodor production was examined. Method and Materials: Malodor production levels were scored by an experienced odor judge. Volatile sulfide levels were measured using a sulfide monitor (Halimeter), and salivary protein degradation was determined densitometrically following electrophoresis on polyacrylamide gel (SDS-PAGE). Microbial population was evaluated by viable counts and microscopy. Results: Whereas all of the various medicinals caused some reduction in malodor production from the incubated whole saliva, echinacea and lavender were the most effective. Conclusion: The bioassay utilized in the present study suggests that these herbs may inhibit oral malodor production. Keywords: natural medicinals, oral bacteria, oral malodor, saliva