Phenylamino benzhydroxamic acid derivatives of the formula ##STR00001## where R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, and R.sub.6 are hydrogen or substituent groups such as alkyl, and where R.sub.7 is hydrogen or an organic radical, are potent inhibitors of MEK and, as such, are effective in treating cancer and other proliferative diseases such as psoriasis and restenosis.