Objectives The objective of this evaluation was to assess the feasibility of implementing a fully-integrated, automated, electronic Patient Reported Outcome Measures (ePROM) system into a hospital Electronic Patient Record (EPR) (hospital-based clinical record). Additional objectives included evaluating the effect of the system on PROM completion rates and investigating the acceptability of the ePROM. Methods The evaluation was conducted in a rheumatology clinic in a specialist children’s hospital in the UK. Paper-based Childhood Health Assessment Questionnaire (CHAQ) PROMs were already used in the clinic and an EPR was the main hospital information system. The technical feasibility of introducing the ePROM technology was assessed using a case study approach; the effect of the system on PROM completion rates was investigated using a before-after design; and acceptability was assessed using semi-structured questionnaires and a focus group. Results An automated and integrated ePROM system was successfully implemented in April 2021. Following implementation approximately 500 automated SMS invitations to complete ePROMs were sent to care-givers each month. PROM completion rates increased from 33/100 (33%) to 47/65 (72%) after the introduction of the ePROM system (chi-square = 11.51; p < 0.05). The ePROM system was highly acceptable to patients and clinical staff. Some clinical staff expressed a concern that an electronic system may represent a barrier to care for families with more limited resources. Conclusions High levels of automation and integration with existing technology systems seemed to be key contextual factors associated with the successful implementation and adoption of the ePROM intervention in a paediatric rheumatology clinic.