there is nothing called a good p/e ratio for any of the scrip. the main use of p/e ratio is to compare any company with another. whichever company has a lesser p/e ratio, it is considered to be underpriced. further during market boom, a p/e ratio of even 5 may be considered good. whereas during bearphase (like now), even a p/e ratio of 1 or 2 may be considered good. Hence there is no concept or no constant p/e ratio which can be considered as good