Diagnostic and treatment strategies for gastrointestinal stromal tumors (GISTs) have evolved greatly since the introduction of molecularly targeted therapies. Although several clinical practice guidelines are extant, such as those published by the National Comprehensive Cancer Network and the European Society of Medical Oncology, it is not clear as to whether these are appropriate for clinical practice in Japan. Therefore, clinical practice guidelines for the optimal diagnosis and treatment of GIST tailored for the Japanese situation have often been requested. For this reason, the Japanese Clinical Practice Guideline for GIST was proposed by the GIST Guideline Subcommittee, with the official approval of the Clinical Practice Guidelines Committee for Cancer of the Japan Society of Clinical Oncology (JSCO), and was published after assessment by the Guideline Evaluation Committee of JSCO. The GIST Guideline Subcommittee consists of members from JSCO, the Japanese Gastric Cancer Association (JGCA), and the Japanese Study Group on GIST, with the official approval of these organizations. The GIST Guideline Subcommittee is not influenced by any other organizations or third parties. Revision of the guideline may be done periodically, with the approval of the GIST Guideline Subcommittee, either every 3 years or when important new evidence that might alter the optimal diagnosis and treatment of GIST emerges. Here we present the English version of the Japanese Clinical Practice Guideline for GIST prepared by the GIST Guideline Subcommittee.