Abstract: Phytochemicals present in medicinal plants have health benefits and antimicrobial activity against some pathogenic bacteria. However, little research has been undertaken on the antifungal activity of these extracts. This research aim at testing the antifungal activity of organic ethanol extracts of onion (Allium cepa), ginger (Zingiber officinale) and garlic (Allium sativum) against three fungal isolates (A. flavus, A. niger and C. herbarium) in Potato Dextrose Agar (PDA). Filtered plant extracts were obtained using ethanolic extraction method. Antifungal sensitivity testing was undertaking using the pour plate technique and results obtained by measuring diameter of fungal growth over a 7 day incubation period. All organic plant extracts inhibited growth resulting in a marked significant difference (p<0.01) in growth diameter of fungi on media with extracts compared with same fungi on Potato Dextrose Agar without extracts. Ginger had the highest antifungal activity on all test fungi with a mean diameter of 1.40 cm followed by garlic (1.70 cm) and onion (1.80 cm) respectively whilst A. niger (2.54 cm) showed the highest resistance to the plant extracts followed by A. flavus (2.50 cm) and C. herbarum (1.18 cm). All plant extracts inhibited any observable growth pattern in C. herbarum for a 2 day period and <1 cm growth diameter in A. Flavus and A. Niger whilst the least growth measurement after day one of incubation in PDA only was >2.0 cm. This study confirms the antifungal potential of these plant extracts on the test fungi and suggests the possibility of employing them in food preservation were spoilage is mainly caused by fungi.