Background Updating is an important process for maintaining recommendations’ and clinical practice guidelines’ (CPGs) validity. CPGs methodological handbooks are designed to provide guidance on developing and updating CPGs, however, little is known about this guidance about the updating process.

Objectives To identify and describe the guidance about the updating process in CPGs handbooks.

Methods We included methodological handbooks that provide guidance about updating. We conducted a systematic search in the Guidelines International Network library, US National Guidelines Clearinghouse, MEDLINE and contacted main institutions. For extracting data we developed a list of key elements.

Results We included thirty-six handbooks. Most of them (97%) focus mainly on developing de novo CPGs and include some information about updating. Half of the handbooks provide a time frame for updating guidelines. The majority of handbooks do not provide guidance about the updating process, namely: literature search, evidence selection, assessment, synthesis and external review. Finally, two handbooks (6%) provide information about publishing an updated CPG.

Discussion Our study highlights that the updating process is poorly described in current methodological handbooks. Handbooks do not contain enough information for executing an optimal update.

Implications Institutions responsible for updating and developing CPGs need to pay more attention to updating and reflect this in their handbooks. This guidance should be more rigorous, explicit and detailed. This could, consequently, lead to a more optimal updating process and, hence, more up-to-date recommendations.