Performing a knee arthroplasty procedure in a stiff or ankylosed knee is a challenging procedure. Knee stiffness could be due to various causes, some of which may involve additional difficulties and risks in the treatment. A failure to obtain an adequate exposure may lead to technical errors and related complications, on the other hand an extensive soft tissue release may lead to complications and very careful and gentle dissection is required. The causes of preoperative stiffness should be analyzed and the surgeon should be familiar with all the surgical techniques but should choose whichever technique he/she is most comfortable. The severity and the cause of the stiffness affect the clinical outcome thus the expected result and possible complications should be initially explained to the patient using simple, clear terms to ensure the patient has realistic expectations in advance. An aggressive post-operative rehabilitation protocol should be followed in all patients. Although a less than optimal clinical and functional outcome can be achieved in these patients, the improvement in the pain and functional scores of the patients is striking and a better quality of life is provided for the patients.