Objective The purpose of this study was to develop a Self‐Efficacy Scale for Rehabilitation Management designed specifically for postoperative lung cancer patients (SESPRM‐LC) and to evaluate its psychometric properties. Patients and methods Based on the concept of self‐management of chronic disease, items were developed from literature review and semistructured interviews of 10 lung cancer patients and screened by expert consultation and pilot testing. Psychometric evaluation was done with 448 postoperative lung cancer patients recruited from 5 tertiary hospitals in Fuzhou, China, by incorporating classical test theory and item response theory methods. Results A 6‐factor structure was illustrated by exploratory factor analysis and confirmed by confirmatory factor analysis, explaining 60.753% of the total variance. The SESPRM‐LC achieved Cronbach's α of 0.694 to 0.893, 2‐week test‐retest reliability of 0.652 to 0.893, and marginal reliability of 0.565 to 0.934. The predictive and criterion validities were demonstrated by significant association with theoretically supported quality‐of‐life variables (r = 0.211–0.392, P < .01), and General Perceived Self‐efficacy Scale (r = 0.465, P < .01), respectively. Item response theory analysis showed that the SESPRM‐LC offers information about a broad range of self‐efficacy measures and discriminates well between patients with high and low levels of self‐efficacy. Conclusions We demonstrated initial support for the reliability and validity of the 27‐item SESPRM‐LC, as a developmentally appropriate instrument for assessing self‐efficacy among lung cancer patients during postoperative rehabilitation.