Introduction: Many patients are discharged from hospital with a peripherally inserted central catheter in place. Monitoring the peripherally inserted central catheter insertion site for clinical and research purposes is important for identifying complications, but the extent to which patients can reliably report the condition of their catheter insertion site is uncertain. The aim of this study was to assess the inter-observer agreement between nurses and patients when assessing a peripherally inserted central catheter site. Methods: The study was based on inpatients who were enrolled in a single-centre, randomised controlled trial comparing four different dressing and securement devices for peripherally inserted central catheter sites. A seven-item peripherally inserted central catheter site assessment tool, containing questions about the condition of the dressing and the insertion site, was developed. Assessment was conducted once by the research nurse and, within a few minutes, independently by the patient. Proportions of agreement and Cohen’s kappa were calculated. Results: In total, 73 patients agreed to participate. Overall, percentage agreement ranged from 83% to 100% (kappa =.65–.82). For important clinical signs (redness, swelling, ooze, pus and tracking), there were high levels of percentage agreement (99%–100%). Conclusion: The high level of agreement between nurse/patient pairs make the instrument useful for assessing peripherally inserted central catheter–associated signs of localised infection, allergic or irritant dermatitis or dressing dislodgement in a community setting.