This study was carried out on 50 cows clinically affected by acute mastitis in different farms in Assiut Governorate. The clinical symptoms of affected animals have been discussed. The isolated organisms in this study were 61 bacterial isolates and 21 isolates of yeast and fungi, the percentage of bacterial isolates in total infected cases were Staphylococcus aureus 20 (32.78%), Stophylococcus epideramidis 8(13.12%) Streptococcus aglactiae 8(13.12%). Streptococcus dysaglactae 3(4.91%) E.coli 15(24.59%) and C. pyogens 7(11.48%). The isolated yeast and fungi were Aspergillus flavous 6(28.57), Pencillium chrysogemum 3(14.28%) Pencillium cyclopium 3(14.28), Candida speices 8(38.1%) and Geotricum Candidium 1(4.77%). Sensitivity test was carried out by different types of antibiotics, the most isolated bacterial organisms were higtly sensitive to Gentamycine, Chlormphinicol and Erthromycine while they were less sensitive to Tetracycline and resistant to Colistome, Naldizie Acid and Streptomycine. Aquous Garlic solution was experminted to determine its effect on isolated yeast and fungi by using different concentration (2.5%, 5% and 10%) of Garlic solution. It was found that 2.5% of Garlic is effective on Aspergillus and Candida sp < /em>, 5% more effective on all species except Geotericum Candidium, while 10% concentration causes complete inhibition for all types of fungus and yeast isolates.