Objective: The present study aimed to develop and validate a brief digital art therapy package specifically designed to address rumination in individuals with diabetes. Method: This applied research was conducted in three main phases: (a) a preliminary needs assessment using a qualitative phenomenological approach based on an analysis of the lived experiences of patients with diabetes; (b) the design of the art therapy package; and (c) the validation of the package using the Delphi method. Results: Thematic analysis of data from semi-structured interviews with patients revealed four core themes related to their ruminative thoughts: (a) self-blame; (b) failure to externalize thoughts; (c) fear of disease progression; and (d) excessively negative perceptions of diabetes. Following the identification of these themes, four original art therapy techniques were mapped onto these four core themes. The scores assigned to each technique by the experts yielded a Kendall's coefficient of concordance (W = /745) and a significance level (P = /007), indicating excellent inter-rater agreement on the validity of the newly developed art therapy package. Conclusion: Based on the findings, the developed art therapy package can be considered valid; however, further research is needed to evaluate its effectiveness.