Purpose To investigate whether inappropriate prescribing, defined by the Beers Criteria, is associated with medication-related harm (MRH), hospital admission, and mortality in older adults in England. Methods A multicentre, prospective cohort study recruited 1280 patients (median age 82 years) at hospital discharge. Patients were followed-up in the community by pharmacists for 8 weeks to identify MRH (harm from adverse drug reactions, non-adherence, and medication errors) and hospital admissions. One-year mortality was determined using hospital records. Potentially inappropriate medications (PIMs) were determined using the 2015 version of the Beers criteria. Logistic regression was used to investigate the relationship between patients prescribed PIMs and adverse outcomes. Results Two hundred and seventy-six patients (22%) were prescribed one or more PIMs at hospital discharge. The main PIM classes prescribed at hospital discharge were benzodiazepines and related drugs (30%) and antidepressants (27%). 1116 out of 1280 patients completed follow-up and 413 (37%) experienced MRH. In 51 cases (12%), MRH was attributable to a PIM. There was no significant relationship between patients prescribed PIMs and overall MRH, hospital readmission or all-cause one-year mortality. Multiple PIMs at discharge was independently associated with an increased risk of ADR (OR 2.32, 95% CI 1.03-5.23). Conclusion The prescribing of PIMs is common at hospital discharge of older adults in England. The 2015 Beers criteria have a limited clinical value to predict adverse outcomes following hospital discharge in this setting.