This study was carried out to compare effect of some pesticides and bioagents or biocides in controlling onion root rot disease caused by Sclerotium cepivorum (Berk) . In the experiment  field four fungicides (triflumizole , benomyl , thiophanate-methyl and  dimethomorph) , two herbicides  (pendimethalin and butralin) , one insecticides  (KZ oil) , four bioagents (Trichodermaharzianum , T. viride , Bacllius  subtilis and Bacllius pumilius) and four commercial biocides (Plant guard , Biozeid ,  Bio Arc and Rhizo –N )were applied to control this disease under naturally infested field .The tested compounds were treated as seedling treatment and as spray treatment .The results indicated that fungicides in general were the most effective in  reducing disease incidence followed by commercial biocides , herbicides and insecticide (KZ oil) . Also fungicides used were the most effective in increasing plant height , blub diameter , total soluble solids and yield .The best effective biocides was Plant guard followed by Biozeid, Bio Arc and Rhizo –N in controlling onion white root rot disease . The lowest effect was obtained by KZ oil which used mainly as insecticide and herbicides had moderate effect in controlling the disease.