The AGREE II is a revised version of the original AGREE instrument, designed to improve the development, reporting, and evaluation of clinical practice guidelines. The original AGREE instrument, developed by the AGREE Collaboration, was a 23-item tool assessing guideline development and reporting processes. However, it had limitations, such as a four-point response scale not meeting methodological standards and a lack of systematic data on its usefulness. The AGREE Next Steps Consortium addressed these issues by developing AGREE II, which includes a seven-point response scale, revised items, and a new user's manual. AGREE II is more reliable and valid, effectively differentiating between high- and low-quality guidelines. It is recommended as the preferred instrument for guideline development, reporting, and evaluation. The new user's manual provides detailed guidance on rating items, including explicit descriptors for the seven-point scale, definitions of concepts, and examples. AGREE II is available online and is used to evaluate guidelines for cancer control. It has various applications, including guideline development, policy decisions, and clinical practice. The AGREE Research Trust manages the AGREE project and supports ongoing research. AGREE II is supported by the Canadian Institutes of Health Research and is used globally. Other tools, such as a French translation and an online training tool, are being developed. The AGREE II aims to improve the quality and consistency of clinical practice guidelines worldwide.The AGREE II is a revised version of the original AGREE instrument, designed to improve the development, reporting, and evaluation of clinical practice guidelines. The original AGREE instrument, developed by the AGREE Collaboration, was a 23-item tool assessing guideline development and reporting processes. However, it had limitations, such as a four-point response scale not meeting methodological standards and a lack of systematic data on its usefulness. The AGREE Next Steps Consortium addressed these issues by developing AGREE II, which includes a seven-point response scale, revised items, and a new user's manual. AGREE II is more reliable and valid, effectively differentiating between high- and low-quality guidelines. It is recommended as the preferred instrument for guideline development, reporting, and evaluation. The new user's manual provides detailed guidance on rating items, including explicit descriptors for the seven-point scale, definitions of concepts, and examples. AGREE II is available online and is used to evaluate guidelines for cancer control. It has various applications, including guideline development, policy decisions, and clinical practice. The AGREE Research Trust manages the AGREE project and supports ongoing research. AGREE II is supported by the Canadian Institutes of Health Research and is used globally. Other tools, such as a French translation and an online training tool, are being developed. The AGREE II aims to improve the quality and consistency of clinical practice guidelines worldwide.