Objective: This study aimed to determine the mediating role of motivation in the effect of nurse-nurse collaboration on work performance. Material and Methods: The research was carried out as a correlational study using survey questions directed to the participants. One hundred thirty-one nurses who continued their active duties participated in the study. Within the scope of the research, a questionnaire consisting of nurse-nurse cooperation, motivation at work, job performance scales, and descriptive questions were used. All analyzes were done in SPSS version 22 and Hayes Process Macro. In the study, descriptive statistics were used to reveal participant characteristics. Process Macro model 4 was used to test the research hypotheses. Since the hypotheses were one-sided, the p value was accepted as 0.025. Results: As a result of the research, it has been determined that nurse-nurse cooperation directly affects work performance. It is statistically significant that the motivation to this effect has an increasingly positive effect. Conclusion: Nurses working in teams should be in professional solidarity. Because it is known that when the nurse cooperation reaches the desired levels, the motivation of the nurses increases, and it contributes to the best health outcomes for the patients. For higher performance and better health service delivery, it is recommended that hospital and nurse managers increase nurse cooperation and motivation.