The search for new alternatives to preserve foods is a growing research field that is of great interest to the food industry. In this study the inhibitory effect of clove and/or mustard essential oils in vapor phase was evaluated in vitro and in vivo (strawberries) against Botrytis cinerea, a mold highly detrimental to fruits and vegetables. In vitro and in vivo minimum inhibitory concentration (MIC) for clove essential oil was 92.56 μL/Lair while for mustard essential oil was 15.42 μL/Lair. As for the combination of tested essential oils the MIC was 46.28 μL/Lair of clove essential oil and 1.93 μL/Lair of mustard essential oil for the in vitro tests, while 11.57 μL/Lair of clove essential oil and 1.93 μL/Lair of mustard essential oil for the in vivo tests. Furthermore, the observed inhibitory effect is due to a synergism of tested essential oils in most of the assessed combinations.