Background: The clinical and scientific usage of patient-reported outcome measures is increasing in the health services. Often paper forms are used. Manual double entry of data is defined as the definitive gold standard for transferring data to an electronic format, but the process is laborious. Automated forms processing may be an alternative, but further validation is warranted. Materials and Methods: 200 patients were randomly selected from a cohort of 5777 patients who had previously answered two different questionnaires. The questionnaires were scanned using an automated forms processing technique, as well as processed by single and double manual data entry, using the EpiData Entry data entry program. The main outcome measure was the proportion of correctly entered numbers at question, form and study level. Results: Manual double-key data entry (error proportion=0.000 (95% CI: 0.000-0.000)) performed better than single-key data entry (error proportion=0.000 (95% CI: 0.000-0.001), (p= 0.020)). There was no statistical difference between Optical Mark Recognition (error proportion=0.000 (95% CI: 0.000-0.000)) and double-key data entry (p=1.000). With the Intelligent Character Recognition method, there was no statistical difference compared to single-key data entry (error proportion=0.007 (95% CI: 0.001-0.024), (p= 0.656)), as well as double-key data entry (error proportion=0.003 (95% CI: 0.000-0.019), (p= 0.319)). Discussion and conclusion: Automated forms processing is a valid alternative to double manual data entry for highly structured forms containing only check boxes, numerical codes and no dates. Optical Mark Recognition performed equally as well as manual double-key entering, and better than single-key entering. Regarding Intelligent Character Recognition, we cannot draw firm conclusions due to the limited data available in this study, and therefore further research, as well as improvement in technology, is warranted.