Objective: This study was designed to investigate treatment efficacy and side effects of concomitant Aisu$^{(R)}$ (docetaxel) with three-dimensional conformal external beam radiotherapy for the treatment of inoperable patients with esophageal cancer. Methods: Inoperable patients were treated with three-dimensional conformal external beam radiotherapy (5/week, 2 GY/day, and total dose 60GY) plus docetaxel ($30-45mg/m^2$, iv, d1, 8). Results: Twenty eight patients met the study eligibility criteria and the response rate was evaluated according to RICIST guidelines. Among 28 patients, 2 achieved CR, 22 PR, 3 SD and 1 patient was documented PD. Mild gastrointestinal reaction and bone marrow suppression were also documented. All treatment related side effects were tolerable. Conclusion: Three-dimensional conformal external beam radiotherapy combined with docetaxel is an active and safe regimen for inoperable patients with esophageal cancer.