In present study strong pathogenic capability of the fungus Alternaria alternata was established on pear leaves. The bit placement method was adjudged superior to drop placement and spray inoculation as percent recovery of the disease was higher in bit placement inoculation. The four test isolates exhibited variation in extent of sporulation, pathogenic variability and growth pattern. Bhoonga (Hoshiarpur) isolate was found to be most virulent followed by PAU (Ludhiana) and Attari (Amritsar). None of the four test varieties was found to be resistant or moderately resistant under natural conditions as well as under in vitroand in vivo inoculation conditions. Screening under both in vitro and field conditions showed that Punjab Gold was moderately susceptible to the disease while Patharnakh and Punjab Beauty were susceptible and Punjab Nectar was highly susceptible. It was found that the pathogen survived on the infected fallen leaves, which help in its perrennation.