A laboratory experiment had been conducted to throw light on the fungicidal activities of plant oils camphor oil, citronella oil and cotton seed oil against four species of fungi: P so/ant R. so/ant, S. roils// and T. virile These oils were prepared as emulsifiable concentrates (EC) using different surface active agents, namely: Sodium dodecyl sulphate, PEG 600 monolaurate, PEG 600 dioleate, Tween80 and Tween20, and solvents the xylene, isopropyl alcohol and dimethyl formamide. The physico — chemical properties for surface active agents, solvents, crude oils and prepared oils were measured. The bioassay experiments were designed to evaluate the EC50 for the plant oils against the fungi under investigation. Each plant oil was prepared in serial dilutions: 125, 250, 500, 1000 and 2000 pg/ml in PDA media. The results of bioassay showed that the response of the fungus S. rolfsii for all plant oils used was higher than other fungi under investigation. Also, the study showed that the fungus F. so/ani had more response to the plant oil citronella than for the other plant oils. On the other hand, the response of the fungi R. solani and T. virile to the plant oil camphor was higher compared to the other plant oils under investigation.