Mango (Mangifera indica L: Anacardiaceae) is regarded as the mostliked fruit in tropical and sub-tropical regions of the world. Powdery mildewof mango caused by Oidium mangiferae Bert. is one of the major plant pathological constraints in growing healthymango orchards. The apparent symptoms of the disease occurred on young tissuesof all parts of flowers, leaves and fruits. Severe blossom infection couldresult in complete damage to fruit; flower failed to open and drop off from theinflorescence. The inflorescence revealed a pattern of disease from tip todownward and showed itself by the emergence of wefts of white mycelium on theaffected parts. Twenty-five mango varieties i.e. Langra, Dusehri, Ratole No.12, Fajri, Sindhri, Chaunsa Samar Bahisht, Anwarratole, Neelam, Yakta, Tota Pari, Sensation, Saroli, Malda, Ghulab e Khas,Chaunsa Black, Chaunsa white, Anmol, Almas, Shan e Ali, Shan e Mustafa, MahmoodKhan, Armughan, Zafaran, Malda Late and Early Gold were evaluated through theobservation of symptoms on young inflorescence to determine the diseaseincidence, disease severity index and average yield of fruit. The study wascarried out in a randomized compete block design with twenty-five treatmentsand three replications. The mango varieties presented different performance inrelation to powdery mildew incidence and could be categorized into eightgroups. Maximum disease incidence was observed (33.33%, 26.66% and 26.66%,26.66%) on Dusehri, Chaunsa Samar Bahisht, Malda and Ratole No.12 respectivelyand minimum disease incidence was (3.66% and 3.66%) noted on Almas andSensation. These two varieties showed to be tolerant against the disease. Itmight be concluded that the presence or absence of symptoms caused by thepowdery mildew had no such effect on the fruit yield of the mango cultivars.