You can identify your outliers with the boxplot function itself. Here is an example: (you can just copy it and paste it into R) # This generates a rondom variable x with 10 elements x = rnorm(100) boxplot(x) # you shouldn't see any outliers here although sometimes yow will # lets add some outliers intentionally x = c(21, 20, 25, x) # now 10, 15 and 20 are outliers myboxplot <- boxplot(x) # now you should see your three outliers myboxplot$out # it will print the values of the outliers # additionally, myboxplot stores a series of other useful statistics, try names(myboxplot) # you shold get something like # [1] "stats" "n" "conf" "out" "group" "names" # try for example myboxplot$stats # Hope this is useful to you.