Chronic posterior heel or ankle pain most commonly results from the pathology of the Achilles tendon, its insertion into the calcaneum, or the two associated bursae. Achilles tendinitis or tendinopathy, a very common clinical syndrome, primarily resulting from overuse injuries is often associated with retrocalcaneal bursitis. The purpose of this study was to find out the effect of ultrasound-guided steroid injection at retrocalcaneal bursa in cases of Achilles tendinitis and to correlate its clinical outcome with preprocedural magnetic resonance imaging (MRI) grading. Sixty-nine patients with clinically and MRI proven Achilles tendinitis were included in the study. MRI findings of tendinitis were graded according to severity. Each patient received an ultrasound-guided injection of 40 mg of methylprednisolone and 1–2 mL of 0.25% bupivacaine into the retrocalcaneal bursa. The outcome was determined and was evaluated in relation to the preprocedural MRI findings. Fifty-seven patients reported at least some relief of symptoms after a follow-up period of 6 months while 12 patients showed no improvement. Shorter duration of symptoms and minor grade MRI findings were associated with complete resolution. Ultrasound-guided steroid injection in retrocalcaneal bursa may be of benefit in the short-term management of clinically and MRI proven Achilles tendinitis.