Objective To explore the real experiences of reciprocal behavior at the workplace of ICU nurses, and to provide a refe-rence for promoting the construction of ICU nursing team.Methods A semi-structured interview was conducted among 15 ICU nurses by phenomenological approach.Colaizzi seven-step analysis was used to analyze the data.Results Four themes were identified: the characteristics of ICU nursing work determined the universality and positivity of reciprocal behavior; reciprocal behavior of ICU nurses at the workplace was diverse; reciprocal behavior of ICU nurses was influenced by context and was time-dependent; and nursing managers supported reciprocity in the workplace.Conclusion The reciprocal behavior at the workplace has positive effects on ICU nurses.Nursing managers can leverage the characteristics of workplace reciprocal behavior to enhance teamwork and create a more harmonious work environment.