[Purpose] The aim of this longitudinal study was to examine the long term functional effectiveness of proprioceptive neuromuscular facilitation (PNF) after total knee arthroplasty. [Subjects and Methods] We included 30 patients and they were randomly assigned to two groups. In addition to the standard rehabilitation program the PNF group received proprioceptive neuromuscular facilitation therapy and the CPM group received continuous passive motion therapy. The outcome measures included range of motion using a goniometer, pain scores using a numeric pain rating scale, days to reach functional benchmarks, the Beck depression scale and isokinetic torque and isometric strength measurements. [Results] There were no significant differences between the two groups in terms of baseline demographic data, clinical findings and length of stay. Days to reach range of motion benchmarks were similar in the two groups. Pain at the 8th week was slightly higher in the PNF group. With the exception of walking with a walker, days to reach functional benchmarks were statistically significantly fewer in patients of the PNF group despite similar isokinetic measurements. Administration of PNF resulted in earlier functional gains in patients after total knee arthroplasty. These functional accomplishments were more pronounced in the PNF group despite it having isokinetic torque measurements similar to those of the CPM group. [Conclusion] PNF techniques can positively affect functional outcomes over the long term.