Mango (Mangifera indica L.) is considered one of the most important fruit for millions of people worldwide, particularly in Egypt where it is deemed to be the choicest of all indigenous fruits. Mango powdery mildew caused by Oidium mangiferae Berthet is a severe disease that infects all parts of mango trees except the fruits. The present investigation aimed to evaluate the use of some eco-friendly compounds as alternatives to control the disease. The obtained results indicate that acetic acid at a concentration of 16.5ml/liter proved to be the most effective eco-friendly compound in decreasing mango powdery mildew disease incidence resulting from the highest efficiency percent in both investigated seasons compared with the tested fungicide propiconazole. Mango plants indicate the highest proline, phenols and protein contents when treated with sulfur. Sulfur was also an inequality with all the other investigated eco-friendly compounds in enhancing oxidative enzyme activities.