Abstract The outcome of 23 Oxford unicondylar knee replacements revised to total knee replacements was assessed with an average follow up of 4.1 years. At revision, 30% of the cases had required reconstruction for bone deficiency. Bone graft, when needed, was obtained from the revision cuts. One patient required re-revision for recurrent sepsis. The remainder included 10 excellent, 3 good, 2 fair and 2 poor results. The poor results were because of instability which could have been prevented by using a more constrained implant. Revision of unicondylar knee replacement is technically easier and results superior to the revision of total knee replacement.