Purpose: Total joint arthroplasty is accompanied by significant costs. In nursing, patient education on financial issues is considered important. Our purpose was to examine the possible association between the arthroplasty patients’ financial knowledge and their out-of-pocket costs.

Methods: Descriptive correlational study in five European countries. Patient data were collected preoperatively and at 6 months postoperatively, with structured, self-administered instruments, regarding their expected and received financial knowledge and out-of-pocket costs.

Findings: There were 1,288 patients preoperatively, and 352 at 6 months. Patients’ financial knowledge expectations were higher than knowledge received. Patients with high financial knowledge expectations and lack of fulfillment of these expectations had lowest costs.

Conclusion: There is need to establish programs for improving the financial knowledge of patients. Patients with fulfilled expectations reported higher costs and may have followed and reported their costs in a more precise way. In the future, this association needs multimethod research.