This study aimed to determine the effects of kinesiotape (KT) on pain, range of motion, and functional status in patients with osteoarthritis of the knee. In this randomized controlled trial, patients with knee osteoarthritis, based on American College of Rheumatology criteria, and Kellgren-Lawrence grade 2 or 3 criteria were selected. Visual analogue scale and active range of motion were the primary outcome measures. Timed Up and Go test and 6-min walk test, were the secondary outcome measures. Evaluation was performed at baseline (T0), after 1 hr (T1), and after 72 hr (T2). We recruited 27 patients with osteoarthritis (age, 57.33±8.72 years; 63% female; body mass index, 29.7±4.3 kg/m) who were randomly assigned into KT or sham-KT groups. There was a significant group by time interaction for the visual analogue scale (< 0.001, =0.593), active range of motion (flexion) (<0.001, =0.492), active range of motion (extension) (<0.001, =0.351), 6-min walk test (<0.001, =0.568), and Timed Up and Go test (=0.026, =0.136). Between-group comparisons revealed significant differences between KT and sham-KT in visual analogue scale and Timed Up and Go test in T1 and T2 assessments, with changes in knee flexion (<0.002) and extension active range of motion (<0.010) and 6-min walk test (<0.044) at 72-hr posttreatment. This study showed that, 1 hr of KT is an effective treatment for decreasing pain and improving active range of motion and physical function at a 72-hr follow-up in patients with osteoarthritis.