Background: C-reactive protein point-of-care testing (CRP-POCT) has been shown to reduce antibiotic use in patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD) in primary care by 26%, without compromising patient care. Fewer than half of AECOPD patients present with bacterial aetiology and further safe reductions may be possible. Aim: To investigate the associations between presenting features and antibiotic prescribing in patients with AECOPD in UK primary care. Design and Setting: This was a secondary analysis of a randomised controlled trial of participants presenting with AECOPD in primary care. Method: Clinicians collected participant’s demographic features, comorbid illnesses, clinical signs, and symptoms. Antibiotic prescribing decisions were made following participants being randomised to receive a point-of-care CRP measurement. Multivariable regression models were fitted to explore the association between patient and clinical features and antibiotic prescribing and extended to further explore any interactions with CRP measurement category (CRP not measured, CRP <20mg/L, CRP ≥20mg/L). Results: We included 649 participants from 86 general practices across England and Wales. The odds of antibiotic prescribing were higher in the presence of clinician-recorded crackles (adjusted odds ratio (AOR)=5.22,95%CI:3.24-8.41), wheeze (AOR=1.64,95% CI:1.07-2.52), diminished vesicular breathing (AOR=2.95,95%CI:1.70-5.10), or evidence of consolidation (AOR=34.40,95% CI:2.84-417.27). Increased age was associated with lower odds of antibiotic prescribing (AOR per-year increase =0.98,95% CI:0.95-1.00), as was the presence of heart failure (AOR=0.32,95% CI:0.12-0.85). Conclusion: Several demographic features and clinical signs and symptoms are associated with antibiotic prescribing in AECOPD. The diagnostic and prognostic value of these features may help identify further safe reductions.