Five fungal isolates were isolated from infected tomato seedlings showing damping-off which collected from several tomato nurseries of Assiut and New Valley Governorates, Egypt. These isolates were Rhizoctonia solani Kühn, Fusarium oxysporum f.sp. lycopersici Schlechtendahl, Fusarium semitectum Berk. & Rav., Setosphaeria rostrata Leonard and Alternaria alternata (Fries) Keisler. Also, tomato seed treatments with Humic acid, Algae (Kelpak), Silicon (Potassium silicate) and Fungicide Topsen M (positive control) significantly reduced the disease percentage and disease severity of damping-off on tomato seedlings compared with untreated infected plants. Topsen M treatment markedly and completely inhibited disease percentage of damping-off compared with other tested compounds. The most effective application of commercial compounds was find when tomato seeds were treat with Potassium silicate.