The purpose of the present invention is to prevent, treat or alleviate peripheral nerve disorders caused by anti-cancer agents satisfactorily and sustainably. The present invention provides a prophylactic, therapeutic or alleviating agent for peripheral nerve disorders caused by anti-cancer agents, said prophylactic, therapeutic or alleviating agent being intended to be administered non-topically and containing a PKC inhibitor or a MEK/ERK pathway inhibitor as an active ingredient. The present invention also provides a prophylactic, therapeutic or alleviating agent for peripheral nerve disorders caused by anti-cancer agents, said prophylactic, therapeutic or alleviating agent containing a MEK inhibitor or an ERK inhibitor as an active ingredient.