'mismanage' originates from the prefix 'mis-' (Old English/Proto-Germanic) meaning 'wrongly' or 'badly' combined with the verb 'manage', which comes from Italian 'maneggiare' (from Latin 'manus' meaning 'hand').

'manage' changed from Italian 'maneggiare' (and Old French forms such as 'mesnage/menager' / 'maneger'), entered Middle English as forms like 'managen', and eventually became the modern English 'manage'; the word 'mismanage' was formed by adding the prefix 'mis-' to this verb in Early Modern English.

Initially, 'manage' had senses related to handling by hand and controlling; with the prefix 'mis-' the combined form originally meant 'to handle wrongly' and has evolved into the current sense 'to manage badly or incompetently'.