Antimicrobial resistance (AMR) is challenging all aspects of healthcare. Increasing antibacterial exposures are selecting out resistant isolates and increase the risk of future infective complications. Through antimicrobial stewardship activities, we aim to minimise the impact of AMR by optimising early empiric treatment and minimising unnecessary antibacterial prescribing. Optimising duration of therapies is one of the key interventions to allow personalised treatment. Ensuring the shortest effective duration is key to providing the most effective whislt minimising unnecessary toxicity. Here we discuss options for personalising antimicrobial durations