Objectives: Time-to-treatment initiation is an important consideration for patients undergoing thoracic surgery for early-stage lung cancer because delays have the potential to adversely affect outcomes. This study seeks to quantify time-to-treatment initiation for patients with clinical stage I lung cancer, explore patient factors and predictors that lead to an increased time-to-treatment initiation, and compare surgeon perception of appropriate time-to-treatment initiation to the results., Methods: Time-to-treatment initiation was determined for patients enrolled in the Mount Sinai Initiative for Early Lung Cancer Research on Treatment study who underwent surgical resection for clinical stage I lung cancer between March 2016 and December 2021. The following dates were determined: (1) date of first suspicious radiologic imaging, (2) date of first biopsy, and (3) date of surgery. A total of 15 thoracic surgeons who participated in the Mount Sinai Initiative for Early Lung Cancer Research on Treatment were assessed on their perception on time-to-treatment initiation., Results: For 638 patients, median time from first suspicious imaging findings to biopsy was 40 days, biopsy to surgery was 37 days, and suspicious imaging to surgery was 84 days. Significant factors that resulted in longer time-to-treatment initiation in the multivariate analysis were African American or Black race ( P = .005), vascular disease ( P = .01), and median household income less than $75,000 ( P = .04). Although the surgeon's perception was that the average time from biopsy to surgery was 28 days, it was longer for 63.5% of participants; surgeon perception of maximum time between diagnosis and surgery was 84 days and longer for 28.7% of participants., Conclusions: Patient factors such as race, income, and comorbidities were found to have differences in time-to-treatment initiation. Delays to surgery exceeded the expectations of thoracic surgeons., Competing Interests: D.F.Y. is a named inventor on a number of patents and patent applications related to the evaluation of chest diseases including measurements of chest nodules; has received financial compensation for the licensing of these patents; is a consultant and co-owner of Accumetra, a private company developing tools to improve the quality of CT imaging; is on the advisory board and owns equity in HeartLung, a company that develops software related to CT scans of the chest; is on the medical advisory board of Median Technology that is developing technology related to analyzing pulmonary nodules; and is on the medical advisory board of Carestream, a company that develops radiography equipment and has consulted for Genentech, AstraZeneca, and Pfizer. C.I.H. is an inventor of the patents and pending patents owned by Cornell Research Foundation (as of April 2009, she has divested herself of all royalties and other interests arising from these) and is on the medical advisory board for LungLife AI. All other authors reported no conflicts of interest. The Journal policy requires editors and reviewers to disclose conflicts of interest and to decline handling or reviewing manuscripts for which they may have a conflict of interest. The editors and reviewers of this article have no conflicts of interest., (© 2024 The Author(s).)