Introduction: Recognition the nurses' communicative roles can influence quality of patient's care. Therefore, this study was aimed to explore nurse's role in nurse-patient relations. Methods: This study was a qualitative research in which collected data was analyzed by content analysis method. The participants were 23 nurses, patients and their families in medical and surgical wards of a referral hospital in Tehran, Iran. Data were collected by semi-structured interview and observation. Results: Data analysis was led to the emergence of a main conceptual category: The patient's need-based communication. This category was derived from two categories: 1) Identifying the patient's needs; and 2) Communicative behavior in the face of the patient's needs. "Identifying the patient's needs" was related to "type of the patient's problem", "patients' inquiring about their health status" and "monitoring the patient's health status". "Communicative behavior in the face of the patient's needs" was composed of four subcategories: "caring attention", "informal education of the patient", "inducing calmness to the patient", and "obtaining the trust of the patient". Conclusion: The nurse's role in relationship with patients is designed according to patients' needs. Therefore, if the patients' needs in clinical settings are defined and clarified appropriately, the nurse-patient relations will be enhanced and thereby the quality of care will be improved.