Brazil has the third largest prison population in the world. Studies on the health status of prisoners have shown that skin diseases, especially infectious skin diseases, are prevalent in this population. Because some skin diseases can be prevented, strategies to inform and guide incarcerated persons may be helpful. PURPOSE The purpose of this study was to develop and validate a manual of skin care for use by prisoners in the Sao Paulo State Prison System. METHODS To develop the manual, a Google search to ensure originality of the concept was conducted, followed by an integrative literature search of the MEDLINE and the Latin American and Caribbean Health Science Literature, and the medical records of the prison system were reviewed for content. The Delphi technique was used to validate content; the content validity index (CVI) was determined based on the ratings of an expert panel of 10 prison employees who were health professionals and have experience providing care to prisoners. Twenty (20) target-users (prisoners) also evaluated the manual. The experts responded to questionnaires (sent by email) containing 19 items related to the manual's objective, structure and presentation, and relevance. Items were rated on a Likert-type scale where 1 = inadequate, 2 = partially inadequate, 3 = adequate, 4 = very adequate, and NA = not applicable, and participants also could provide suggestions and comments on the manual. The prisoners used a paper-and-pencil questionnaire to assess the manual that included 14 items with 3-choice answers (agree, undecided, disagree) on the utility and ability to understand the manual topics and space to write concerns and suggestions regarding the utility of the content; they also could offer their thoughts and opinions about the manual. The proportion of agreement among responses was calculated. RESULTS The overall CVI of the first round of evaluations was 1.0. Suggested changes were to include guidelines on the proper use of medications and modify some wording. The overall CVI of the next round was 1.0 (100% agreement). The evaluation by target users showed an agreement of 98.6%. The final version of the manual has 8 topics, 12 subtopics, and 29 illustrations; topics include skin, hair, and nail care and skin diseases. A printed version is available in the prison library and an electronic copy was sent to all prisons in the State of Sao Paulo to be printed as needed. CONCLUSION A manual providing guidelines on skin care for prison populations was developed and validated with the intent to improve prisoner quality of life and care. Research to examine overall manual usage and the effect of the information and guidance on healthy behaviors, prevention, and management of skin diseases is warranted.