We investigated whether discoloured sputum and feeling unwell is associated with antibiotic prescribing and benefit from antibiotic treatment for acute cough/lower respiratory tract infection in a prospective study of 3402 adults. in 13 countries. A two-level model investigated the association between producing discoloured sputum or feeling generally unwell and an antibiotic prescription. A three-level model investigated the association between an antibiotic prescription and symptom resolution. Patients producing discoloured sputum were prescribed antibiotics more frequently than those not producing sputum (OR: 3.2, 95% CI: [2.1, 5.0]), unlike those producing clear/white sputum (OR: 0.95, 95% CI: [0.61,1.48]). Antibiotic prescribing was not associated with greater rate or magnitude of symptoms score resolution (as measured by 13 item scale completed by patients each day) among those who: produced yellow (Coefficient: 0.00, p-value: 0.68) or green sputum (Coefficient: ?0.01, p-value: 0.11); reported any of three categories of feeling unwell; produced discoloured sputum and felt generally unwell (Coefficient: ?0.01, p-value: 0.19). Adults with acute cough/LRTI presenting in primary care with discoloured sputum were prescribed antibiotics more often compared to those not producing sputum. Sputum colour, alone or together with feeling generally unwell was not associated with recovery or benefit from antibiotic treatment.<br/