Introduction. Providing adequate care for people with venous leg ulcers (VLUs) can be a challenge. Numerous publications have discussed the importance of compression therapies on the treatment of VLUs, but few have described the necessary materials and techniques for applying the Unna boot, contributing to the underutilization of this therapy. The use of manuals is one of the strategies in the training of health professionals. Objective. The aim of this study was to develop and validate a manual on the technique of applying the Unna boot in patients with VLUs. The manual was created to improve the education and training of health professionals in the control of chronic VLUs. Materials and Methods. This was a descriptive study involving 3 stages. The selection of content for the manual was based on a literature review of articles in the Portuguese, Spanish, and English languages published from January 2000 through December 2018, in which 8 key terms were searched across the Cochrane Library, MEDLINE, and SciELO databases, and Google Scholar search engine. The text, illustrations, and layout design of the manual as well as a video demonstration of the technique were created. The manual then was validated for content by an expert panel using the Delphi Technique and the content validity index (CVI). Results. The manual showed an overall CVI of 0.98 after 2 rounds of consultation and its content, presentation, and relevance were rated as very adequate by the expert panel. The final version of the manual features 29 pages of text and illustrations and includes a video demonstration of the technique. Conclusions. A manual on the technique of applying the Unna boot in patients with VLUs was developed and validated for content by an expert panel.