Aim: To establish a simple, rapid, and accurate method for determination of erythrocyte sedimentation rate (ESR) by using capillary tubes in in vivo experimental models. Methods: Adjuvant-induced arthritis (AIA) was established in male Sprague-Dawley (SD) rats, and blood specimens were collected from the veins of the tails of AIA and control rats for determination of ESR using the Westegren or capillary tubes. Different angles of incline of the capillary tubes and durations of ESR determination were screened. Results: The angle of incline of th...