An investigation was carried out with six genotypes of green gram grown under protected (Control) and unprotected conditions against powdery mildew to study the influence of disease on yield and yield components during kharif, 2000.  The results revealed that the yield components were affected by powdery mildew.  There was reduction in the number of pods per plant (29%), number of seeds per pod (27%) and test weight (13%) over the protected treatment.  However, pod length showed only genotypic variation and was not influenced by the disease.  The reduction in yield was observed to be 30% over the control, indicating that the reduction in yield components lead to reduction in the yield.