Sore throat and acute sinusitis are not straightforward diagnoses. Trying to guess the responsible pathogen may not be the best approach. Being guided by empirical evidence may be more useful. It suggests some, but very few, benefits for antibiotics. This has to be balanced with some, but few, harms from antibiotics, including diarrhoea, rash and thrush. Prescribers should also be aware of the risk of antibiotic resistance for the individual, as well as for the population as a whole. GPs should explain the evidence for the benefits and the harms of antibiotics to patients within a shared decision-making framework.