Background The 2018 ESC/ESH guidelines for the management of arterial hypertension in adults aged ≥65 years recommend a blood pressure (BP) treatment target of 130–139/70–79 mmHg if tolerated. Randomised controlled trials have recommended lower BP. However, low BP may cause adverse outcomes, especially in the frail.We aimed to identify if older adults, frail and non-frail, in wave 1 of TILDA being treated intensely for hypertension experienced more adverse events by wave 2. Methods Data from participants aged ≥65 years treated for hypertension in Wave 1 was analysed.Frail/non-frail was identified by Frailty Phenotype (FP) and the Clinical Frailty Scale (CFS).Two blood pressure thresholds defined intensive control: Results 1,920 participants at Wave 1 were aged ≥65 years and treated for hypertension. 1,229 participants had full BP/FP data, while 1,288 had complete BP/CFS data.The frail by FP with treated BP >130/70 or > 110/70 had a statistically significant risk of new TIA or stroke by Wave 2.The frail by CFS with treated BP >130/70 or > 110/70 had a statistically increased risk of recurrent falls and/or fractures, as did the frail by FP with treated BP >110/70. FP with treated BP Conclusion Frail older adults treated to higher BP thresholds seemed to have more adverse short-term health outcomes compared to the frail treated more intensely. Overall, a BP of