Background: Nursing code of ethics is an essential part of nursing professional practice. Nurses' adherence to a code of ethics is an important pillar of improving their performance, providing good nursing care and achieving patient satisfaction. This study aimed to examine relationship between nurses' adherence to an Egyptian professional nursing code of ethical practice and patient satisfaction with quality of nursing care in critical and medical-surgical care units. Subjects and Method: Study design: A cross-sectional descriptive correlational study. Setting: Critical and medical-surgical care units in Alexandria Main University Hospital. Subjects: The study was implemented on 400 nurses and 400 patients.  Study tools:  Data were collected using an observational checklist of nurses' adherence to the Egyptian code of ethical practice and a patient satisfaction questionnaire. Results:  The nurses' adherence to the code of ethical practice and patient satisfaction with quality of nursing care were found to be below a satisfactory level in critical (48.5%, 43.0, respectively) and medical-surgical care units (46.5%, 37.5%, respectively). There was no significant difference between critical and medical-surgical care units in mean scores of humanity and patient right respect and provision of nursing practice (p > .05). However, nurses in critical care units had better adherence to the ethics code compared to nurses in medical-surgical care units. Commitment of nurses to the code of ethical practice had a positive significant effect on patient satisfaction with quality of nursing care. Conclusions:  An unsatisfactory level of nurses' adherence to the Egyptian code of ethics was the predictive factor of patient dissatisfaction in the study units. This could be contributed to some management and organizational factors that faced nurses during implementing their roles. Recommendations: Healthcare organizations should continuously help nurses update their ethical practices and adherence to the nursing code of ethical practice in their workplace