Introduction & Objective: Plantar fasciitis is the most common cause of heel pain. Because the cause of this pain is uncertain, there are many treatment methods for it. Our study compares the results of two most common treatments known as steroid injection and plantar fasciitis stretching with each other regard to decrease in pain and improving function. Materials & Methods: 66 patients with heel pain and clinical diagnosis of plantar fasciitis, and for whom other causes of heel pain had been ruled out were studied. They were randomly categorized in two groups. One group was treated with local corticosteroid injection and the other group with plantar fascia stretching exercises. After 2 and 8 weeks, they were evaluated regard to function and pain scores. Results: There is no difference between two groups regard to sex, age, height, weight and body mass index. There was significant decrease in pain and improvement in the function of the group which had corticosteroid injection, but, in the 8th week, the two groups had the same results in both aspects. Conclusions: This study show that after 8 weeks of treatment with both therapeutic methods, the results were the same, therefore, it is better to use the less complicated and less expensive method (i.e. stretching), but in cases which prompt pain relief and better function is desired, corticosteroid steroid injection may be better.