An Internet-based tool for reporting and analysing patient-reported outcomes (PROs) has been developed. The tool enables merging PROs with blood test results and allows for computation of treatment responses. Data may be visualized by graphical analysis and may be exported for downstream statistical processing. The aim of this study was to investigate, whether patients with myeloproliferative neoplasms (MPNs) were willing and able to use the tool and fill out questionnaires regularly. Participants were recruited from the outpatient clinic at the Department of Haematology, Roskilde University Hospital, Denmark. Validated questionnaires that were used were European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire-Core 30, Myeloproliferative Neoplasm Symptom Assessment Form, Brief Fatigue Inventory and Short Form 36 Health Survey. Questionnaires were filled out a parts per thousand yen6 months online or on paper according to participant preference. Regularity of questionnaire submission was investigated, and participant acceptance was evaluated by focus-group interviews. Of 135 invited patients, 118 (87 %) accepted participation. One hundred and seven participants (91 %) preferred to use the Internet-based tool. Of the 118 enrolled participants, 104 (88 %) submitted PROs regularly a parts per thousand yen6 months. The focus-group interviews revealed that the Internet-based tool was well accepted. The Internet-based approach and regular collection of PROs are well accepted with a high participation rate, persistency and adherence in a population of MPN patients. The plasticity of the platform allows for adaptation to patients with other medical conditions.