Introduction: The aim of this study was to determine the frequencyof patients with critical illness polyneuropathy/myopathy followed bymechanical ventilator in the intensive care unit, and to determine therisk factors associated with this condition and discuss them with theliterature. Methods: This study was performed retrospectively (August 2012to August 2017), at a tertiary university hospital in Turkey. A total of31 patients who were on mechanical ventilation and diagnosed withpolyneuropathy/myopathy by electroneuromyography (ENMG) duringpediatric intensive care unit follow-up were included in the study. Datawere collected from patient files and computer system. Demographiccharacteristics of the patients, causes of hospitalization, underlyingdisease, length of the pediatric intensive care unit and hospital stay,length of mechanical ventilation, and treatment modalities wererecorded. Patients without respiratory support and patients onmechanical ventilation without ENMG procedures were excluded. Results: A total of 31 patients were included in the study. Myopathywas present in 5/31 (16.1%) and polyneuropathy in 26/31 (83.9%)patients. Respiratory distress/failure was the most common causeof respiratory support (n=10, 32.3%) and the second most commoncause was post cardiac surgery (n=9, 29%). The diagnosis of 18 (58%)patients were sepsis and 2 (6.4%) patients had multiple organ failure.The mean duration of mechanical ventilation was 27.4±14.1 days,length of pediatric intensive care unit stay was 41.5±24 days, length ofhospital stay was 57.5±27.5 days. Mortality was observed in 5 (16.1%)of 31 patients. Conclusion: Critical illness polyneuropathy and myopathy in intensivecare practice is a condition with increasing frequency and importance.Increased attention to this matter allows to take the necessarypreventions, early recognition and to make the appropriate approach.