the sciatica possesses great general population prevalence, and its treatment tends to solve the nervous compression causes. physiotherapy aims to reduce the symptoms caused by compression. this study aimed to evaluate the effectiveness of therapeutic ultrasound on pain in animals subjected to sciatica experimental model. eighteen rats were used and they were divided in 3 groups: group sg (n=4) submitted to the sciatica and treated with the ultrasound off, group pug (n=7) submitted to the sciatica and treated with pulsed ultrasound 2 w/cm2 (satp; 0,4 - sata) and group cug (n=7) submitted to the sciatica and treated with continuous ultrasound (0,4 w/cm2). the sciatic nerve of the posterior right limb was exposed to the compression with catgut wire in 4 points. in the 3rd postoperative day, the indirect treatment was started (right inferior limb) for four days. in the 9th postoperative day, the direct treatment begins on the surgical procedure area for 5 serial days. the paw elevation time, during the march, of the animal was verified before and after the sciatica, at the 3rd, 6th, 9th and 13th postoperative day. the results demonstrated that the application of the therapeutic ultrasound reduced the pain with both treatments in pug and cug, and it has tended larger effectiveness in the pulsed form.