Described is an experimental verification technique for cesium brachytherapy line source emission. The dose rate levels produced by a line source algorithm are compared with measurements taken around J series stainless steel sheathed cesium sources with a p type semiconductor diode detector. Further study of isodensity contours is undertaken using a film dosimetry technique. The errors involved in using these techniques are assessed. © 1988, American Association of Physicists in Medicine. All rights reserved.