The extensive research already conducted in numerous non-healthcare disciplines has consistently demonstrated the effectiveness of flow in alleviating work-related stress and boosting employee engagement in the workplace. Despite the potential benefits to nursing of improving flow, no valid instrument is currently available to measure the work-related flow experience of clinical nurses. This study was designed to develop the Flow State Scale for Caregiving Tasks (FSS-CT) and to evaluate its psychometric properties in the context of clinical nurses. This study, guided by the flow theory of Mihaly Csikszentmihalyi (1975), employed a three-phase approach to developing and evaluating the psychometric properties of the FSS-CT. Five hundred thirty-six full-time clinical nurses working in hospitals of various levels in Taiwan were recruited via cluster random sampling to participate in an anonymous online survey. The content validity of the developed scale was established through expert panel verification, criterion-related validity was assessed by correlating the scale with the Work-related Flow Inventory, and construct validity was evaluated via explanatory and confirmatory factor analyses. Scale reliability was determined using Cronbach's α coefficient. The FSS-CT, a 12-item Likert scale comprising four domains, was developed. These domains capture the elements of nurses' work-related flow, including professional confidence, merging of action and awareness, balance between skill and challenge, and autotelic experience. The FSS-CT demonstrated high content validity (content validity index > .90) and satisfactory criterion-related validity (coefficient = .55, p < .001). Furthermore, the scale was found to have excellent internal consistency (Cronbach's α = .91). Factor analyses yielded a four-factor structure accounting for 69.34% of the total variance, indicating a good fit for the final model based on recommended goodness-of-fit indices. The FSS-CT is a viable and dependable instrument for assessing the work-related flow experiences of nurses, with the measured outcomes offering to nursing administrators valuable insights into or directions for personnel development and work allocation initiatives.