Most often the simple fact that the path is not what you think it is. Maybe the variable doesn't contain what you are SURE it must. Maybe it contains a little more than you think. A space at the end, a newline maybe. Maybe you forgot to double your backslashes (if you're using Windows). Maybe the current directory is not what you expected. If a -e $variable returns false while you think it should return true print "\$variable=>$variable<\ncwd=>" . getcwg() . "<\n";