Background <p>The financial burden on patients in terms of private out-of-pocket personal costs related to accessing healthcare services has become a growing concern internationally. While healthcare systems and access arrangements differ internationally, private cost to patients and their households remains an under-researched area. The private out-of-pocket costs of attending hospital outpatient consultations in Ireland has not been previously established.</p> Methods <p>We developed a data collection tool to measure the private costs to patients of attending hospital outpatient consultations. Resource items included travel time and expenses, missed work, need for accompanying carers, and care needs for dependents, in addition to demographic details. In the pilot study, the questionnaire was completed by 42 patients attending several hospital outpatient departments in a large teaching public hospital in the west of Ireland.</p> Results <p>The pilot study demonstrated the questionnaire’s feasibility and acceptability. Estimates of private costs per visit showed considerable variability, with a median cost per patient of €131 (Inter Quartile Range €142; range €22-€370). Participants reported attending on average 4 appointments per year (mean 4.26, range 1–20, SD 3.7), giving a mean annual cost of attending hospital clinics of €559 per person. On average, participants spent 1.2&#xa0;h (range 0.1-3.0) travelling to their appointment. Fourteen participants (33%) reported missing work, while 18 (43%) required an accompanying carer, of whom four carers were paid.</p> Conclusions <p>Private costs related to attending outpatient clinics are not insignificant. Formal validation of the data collection tool is required, alongside further studies involving larger, more diverse participant samples to better quantify the financial implications for patients attending outpatient consultations.</p> Registration <p>The study protocol was pre-registered using the Center for Open Science registration portal (08 March 2024).</p>