Background and Aims: In earlier work, we identified that people affected by multiple sclerosis (MS) can have difficulty finding online treatment information that is up to date, trustworthy, understandable, and applicable to personal circumstances, but does not provoke confusion or negative emotional consequences. The objective was to develop online consumer summaries of MS treatment evidence (derived from Cochrane Reviews) that respond to identified treatment information needs of people affected by MS. Methods: A 2-phase mixed-methods project, conducted in partnership with consumers and an MS organisation. Phase 1 included review panels with consumers (Australians affected by MS) and health professionals to test paper-based treatment summaries before development, and pilot testing of the website. Phase 2 involved an online survey after website launch. Results: Eighty-three participants (85% affected by MS) took part. Phase 1 participants strongly endorsed key review summary components, including layering information, and additional sections to aid personal applicability. Participants additionally suggested questions for health professionals. Participants across both phases were receptive to the idea of being provided with Cochrane Review summaries online but were seeking other types of evidence and information, such as personal experiences and the latest experimental treatments, which could not be provided. While the small survey sample size (n = 58) limits application of the results to a broader population, the website was viewed favourably, as a useful, understandable, and trustworthy information source. Conclusion: We describe a partnership approach to developing online evidence-based treatment information, underpinned by an in-depth understanding of consumers' information needs.