Background The effect of patient education before total knee arthroplasty (TKA) is controversial. No consensus exists about the optimal content of educational interventions. In a previous study, we developed and validated an educational booklet on the peri-TKA management of knee osteoarthritis. Purposes Our primary purpose was to evaluate the impact of the educational booklet on knowledge among patients awaiting TKA. Patients and methods This randomized controlled single-blind trial evaluated standard information by the surgeon with or without delivery of the educational booklet 4–6 weeks before primary noncomplex TKA in patients aged 55–75 years with incapacitating knee osteoarthritis. Patients were enrolled at a French surgical center between June 2011 and January 2012. A patient knowledge score was determined at baseline, on the day before TKA, and 3–6 weeks after TKA, using a self-administered questionnaire developed for our previous study. The assessor was blinded to group assignment. Results Of 44 eligible patients, 42 were randomized, 22 to the intervention and 20 to the control group, all of whom were included in the analysis. The groups were comparable at baseline. The intervention was associated with significantly better patient knowledge scores. Conclusions An educational booklet improves knowledge among patients awaiting TKA. A study assessing the impact of the booklet combined with a exercise program would be helpful.