Background: Knee osteoarthritis (KOA) is a very common disorder affecting many people during the aging process which finally results in painful symptoms that disturb their lives.

Purpose: This study was conducted to compare the effects of iontophoresis versus ultrasound (US) on knee osteoarthritis. Methods: Seventy-two subjects diagnosed with KOA according to the American college of rheumatology (grade 2 and 3) participated in this study. Their age ranged from 45 to 60 years old while their BMI ranged from 19 to 30 kg/m². They were allocated into three equal groups; Group A (experimental group 1) received Iontophoresis and traditional treatment. Group B, (experimental group 2), received US and traditional treatment. Group C, (control group), received only traditional treatment. All patients received 3 sessions per week for four weeks. Pain intensity, knee ROM, and functional disability, were assessed using the VAS score, the electronic digital goniometer, and the WOMAC index – Arabic version respectively.

Results: There was a significant decrease in VAS and pain, stiffness and function scores of WOMAC of group A compared with that of group B (p < 0.05) and group C (p < 0.001), There was a significant increase in flexion and extension ROM of group A compared with that of group B and group C (p < 0.001).