This article translates the guidelines for preoperative pulmonary function assessment in patients with lung cancer who will undergo surgery, established by the Japanese Association of Chest Surgery on May 17, 2021, from Japanese to English. The last version of these guidelines was created on April 5, 2011. Over the past decade, changes in clinical practice have occurred that do not align with the current guidelines, prompting a revision in conjunction with the introduction of new evidence this time. This guideline was developed with reference to the internationally adopted GRADE (Grading of Recommendations Assessment, Development, and Evaluation) system. Extraction of evidence, systematic review, and quality assessment are entrusted to each guideline review committee and the Pulmonary Function Assessment Working Group. Committee members are also responsible for determining the selection of evidence and the extraction period, with a particular emphasis on adopting items considered to be of special importance. The recommended assessment and management is categorized into a general overview, pulmonary function assessment, cardiopulmonary exercise test, pulmonary function assessment for lung cancer with interstitial pneumonia, preoperative smoking cessation, and pulmonary rehabilitation. These are described by the strength of recommendation, the strength of evidence, and the consensus rate.