A disease screening nursery of rice germplasm consisting of course and fine varieties was established during the kharif 2007 to determine the source of resistance in rice germplasm against Pyricularia oryzae, the cause of rice blast disease at Rice Research Institute Kala Shah Kaku by artificial inoculum with aqueous spore suspension of the pathogen. The screening revealed that none of the test lines was immune or highly resistant. One line IR-70181-1-1-1 of course type was found to be resistant. Nine lines of the course type displayed moderately resistant response, while none of the fine type lines showed this response. Seventy seven lines of both course (35) and fine (42) rice were found to be moderately susceptible. Twenty four lines of fine rice showed susceptible to highly susceptible response. However, the prevalence of the resistance against rice blast pathogen is more common in the course as compared to the fine germplasm lines of rice Key words: Rice blast, screening, Pyricularia oryzae, resistant, susceptible.