Knee osteoarthritis in patients with achondroplasia is rare. Bowleg deformity is typical but corrective surgery is limited. Thus, primary total knee arthroplasty (TKA) might be challenging due to the particular anatomy. We report on a patient with 11 year's follow-up after a TKA performed maintaining bowleg alignment, using a posterior stabilized, fixed-bearing design. Sequential X-rays showed radiolucencies on the femoral component within two years postoperatively, slightly increasing over time but stable at last follow-up. The Oxford Knee Score showed an excellent result at 11 years. Despite the peculiarities of a case report, TKA without concomitant osteotomies might be an option for such patients. Nevertheless, a thorough discussion about pros and cons is paramount.