The aim of this study was to compare the effect of the beta-adrenergic blocker atenolol and the Angiotensin II type 1 (AT1) receptor antagonist losartan on cognitive function in very elderly hypertensive patients. A total of 120 mild to moderate essential hypertensive (DBP> 90 and< 105 mmHg) patients, aged 75–89 years, were studied. After a 4-week wash-out period on placebo, they were randomized to receive atenolol 50 mg or losartan 50 mg for 24 weeks according to a parallel arm design. At the end of the placebo period and of each active treatment period, BP was measured (by mercury sphygmomanometer, Korotkoff I and V) and cognitive function was evaluated through three different tests (word list memory, word list recall and word list fluency). Both atenolol and losartan were equally effective in reducing SBP (− 22.1 and− 23.1 mmHg, respectively, P< 0.01 vs baseline) and DBP (− 10.3 and− 11.2 mmHg, respectively, P< 0.01 vs baseline). Atenolol treatment did not induce significant changes in any test score, whereas losartan significantly increased the score of both the word list memory (+ 2.2, P< 0.05 vs baseline) and the word list recall test (+ 2.1, P< 0.05 vs baseline). The comparison between losartan and atenolol was significant (P< 0.05) for both memory tests. These data suggest that in very elderly hypertensive patients, chronic AT1 receptor blockade by losartan could improve cognitive function, in particular immediate and delayed memory.