The nursing profession is focused on serving others and has high expectations that each member behaves professionally and ethically, as articulated in nursing codes of practice and conduct. Where these are not upheld, inappropriate and unprofessional workplace behaviors follow. Regrettably, unprofessional behavior is neither new nor constrained to the nursing profession, but is known to negatively impact staff and workplace relationships, and importantly, patient safety and care. The aim of this qualitative study was to explore Iranian nurses’ experiences of professional communication between colleagues in the emergency department. Fifteen individual interviews were conducted. The overarching theme to emerge from the data was workplace communication, supported by two subthemes: unprofessional behavior and stressors in the workplace. Individually and collectively, these subthemes demonstrated staff attitudes and behaviors that are inconsistent with expectations of professional behavior and practice. Management proactively addressing unprofessional workplace behaviors is fundamental to establishing and maintaining positive workplace environments and supporting safe, quality patient care.