Cold plasma (CP) is widely used in the biomedical field, especially in dentistry and skin care but also for surface sterilisation of medical equipment. It has also been successfully used for the decontamination of fresh produce from microorganisms, particularly bacteria that cause food-borne illness. There are limited reports of CP to control plant pathogenic fungi. In this study we investigated the direct effect of CP on three postharvest fungal plant pathogens, belonging to the Colletotrichum genus that we isolated from avocados (Colletotrichum alienum and Colletotrichum floriniae). CP using air as the feed gas was tested for its anti-fungal efficacy against pure cultures and spore suspensions of C. alienum and C. floriniae, following treatment for 3 or 6 minutes duration at a distance of 5 cm. The 6 minute CP treatment significantly reduced the radial mycelial growth of freshly inoculated cultures compared to the control. In addition, the 6 minute CP treatment of spore suspensions resulted in almost 100% reduction of spore germination, immediately after treatment. In contrast, the 3 minute CP treatment did not significantly reduce the radial mycelial growth of fresh or actively growing cultures, but did suppress the germination of spores after 15 hours of treatment. These results demonstrate the potential of CP for the control of Colletotrichum species associated with avocado.