OBJECTIVE To determine how frequently stress ulcer prophylaxis (SUP) medications prescribed in the intensive care unit are inappropriately continued on the ward and on hospital discharge. DESIGN Retrospective cohort study; chart review. SETTING Two Australian ICUs: one tertiary centre and one metropolitan centre. PARTICIPANTS We included 387 adult, non-pregnant patients who were admitted to the ICU between 1 February 2011 and 31 March 2011 and who survived to hospital discharge. MAIN OUTCOME MEASURES Rate of unnecessary continuation of ICU-prescribed SUP medications on the ward and on discharge from hospital. RESULTS While in the ICU, 329 of the 387 patients (85%) were prescribed SUP medications. Of the 233 patients who had not been taking acid-suppressive medications before admission to the ICU, 190 were prescribed SUP medications in the ICU. Of these 190 patients, most (63%) had their SUP continued in the ward without any obvious indication, and many (39%) had their SUP medications inappropriately continued on discharge from hospital. CONCLUSIONS SUP medications commenced in ICU are frequently continued unnecessarily, both in the wards and hospital discharge.