Lateral epicondylitis or Tennis elbow is very common repetitive stress injury or cumulative trauma disorder among active professionals and tennis players. Local steroid injection can provide quick functional improvement as sought by most of the patients. Therapeutic ultrasound and eccentric exercises can also improve the function. This study was carried out to see the comparative efficacy of these two modalities of treatments in terms of quicker functional improvement and this randomized interventional clinical trial was carried out in a private rehabilitation hospital in Dhaka. Patients attended the authors private chamber from January 2013 to December 2013 with clinical diagnosis of tennis elbow were included. Eighty adult patients diagnosed as lateral epicondylitis or tennis elbow were randomly divided into two groups. Group A received local steroid injection (triamcinolone acetate) and group B received therapeutic ultrasound for two weeks. Both the groups received eccentric exercises and advised to avoid provocative activities like twisting and lifting activities. Pain, tenderness and functional improvements were measured in traditional methods like visual analogue scale (VAS) and tenderness grade 0 to 4. Data were analyzed by SPSS. Most of the patients were female. None of them were tennis player. Younger housewives were common sufferer. Almost all patients in group A had very little or no pain or tenderness and no difficulty in lifting object at one week and two weeks. VAS was 13.62±6.503 and 4.15±5.517 respectively. Group B patients had mild improvement of pain and function at one week and moderate improvement at two weeks. VAS was 52.57±7.80 and 25.57±5.392 respectively. Similarly tenderness' were markedly improved in Group A at one and two weeks. They were 0.68±0.616 and 0.02±0.405 respectively for Group A and 1.60±0.553 and 1.14±0.335 respectively for Group B. Results were statistically significant in both groups at the end of two weeks. Local corticosteroid injections at extensor origin in tennis elbow patients are found to have better relief of pain and tenderness and quicker functional improvement than therapeutic ultrasound treatment. None of the patients were followed up for long term efficacy in either group.