Abstract: Wet bubble disease of white button mushroom (Agaricus bisporus) is the main constraint in the speedy development of this crop in the valley. The pathogen of this disease, is Mycogone perniciosa, which result either in the partial or total failure of the crop. The aim of the present study was to check the status and yield losses due to wet bubble disease of white button mushroom (Agaricus bisporus) at Mushroom Research and Training Centre of the SKUAST of Kashmir. In the present study, disease incidence, disease intensity and yield losses due to the pathogen were recorded in important mushroom units of Kashmir division, in order to check the frequency of prevalence of wet bubble disease. The survey revealed that wet bubble disease was prevalent in all mushroom growing districts in the range of 33.0 to 67.0%. With the overall mean disease incidence of 9.09% over years in three districts, the disease incidence was more (10.55-14.25%) in spring than in autumn season (3.61-8.05%). Similarly, the overall disease intensity was 17.82% over the years in these districts with more (16.86-28.31%) in spring than in autumn season (9.81-15.46%). The% yield loss over the years due to the disease ranged from 13.53 -22.41% with maximum loss reported in district Pulwama and minimum in district Srinagar. With an overall yield loss of 16.97% over the years, the loss was highest (15.88-26.01%) in spring than in autumn season (8.63-14.92%). The fungal pathogen constantly associated with the disease was established as Mycogone perniciosa. The pathogen produced typical and characteristic symptoms of wet bubble disease.