Work-related activities during non-work time may influence the intershift recovery of post-work fatigue. Currently there is no valid and reliable scale available to measure the frequency for such activities among doctors. Therefore, this study aims to develop and validate 'Work-Related Activities during Non-Work Time Scale' (WANTS) that measure the frequency of work-related activities during non-work time for doctors. This was a scale development and validation study among doctors involving item generation, content and construct validation, and reliability assessment. 23-item seven-point Likert-type scale was developed through deductive (literature search) and inductive (interview with source population, authors' experiences, and expert opinion) methods. The content-validated scale was pre-tested, and the improved scale was subsequently administered to randomly-selected 460 doctors working at public hospital setting. Response rate was 77.76% (n = 382). Initial exploratory factor analysis (EFA) with principal axis factoring (PAF) using varimax rotation revealed unstable six-factor structure consisting of 17 variables; thus, we tested one- to six-factor model, and found that four-factor model is the most stable. Further analysis with principal component analysis (PCA) with a single component on each factor found that 17-variables four-factor model is stable. These factors were labelled as 'work-related thought', 'work-to-home conversation', 'task spillover' and 'superior-subordinate communication'. It showed good internal consistency with overall alpha value of 0.837. The scale is thus valid and reliable for measuring the frequency of each construct of work-related activities during non-work time among doctors.