When COVID-19 pandemic out broke in Italy, during the lockdown from March to May 2020, Inborn Errors of Metabolism (IEM) patients were at risk of not getting their dietary special products and routine visits. Moreover, during pandemic, psychological difficulties might have arose in these subjects, even more severe than in the general population due to the worries about acute decompensation caused by a possible COVID-19. In order to evaluate the patients’ perception of the outbreak situation and their related needs, three simple online anonymous surveys drawn up by Google Forms were sent to patients and families referring to our Adult IEM Center. Answers were collected between April and May 2020. Questionnaires investigated nutritional and lifestyle changes and psychological status using validated psychological tools. 19 patients with IEM filled out our survey (Median age 26-30 years). The most common nutritional therapy was low protein diet. During quarantine 12% patients failed to follow their usual medical diet, 65% reduced their physical activity and no one underwent an acute metabolic crisis. 57% of patients asked for more frequent access to the reference center. 33% of patients showed stress perceived of clinical relevance and general health perception were out of normal in 40% of patients. In conclusion, during quarantine some patients reported difficulty in following their medical diet or physical activity and were clinically stressed. Despite this, no one experienced a metabolic crisis, but asked for contacting the Metabolic Team in different ways than usual due to worries about their health condition. Telemedicine, the possibility of clinical follow-up at home patient (Including blood tests) and reservation of non-COVID-19 beds for hospital admission of IEM patients may have contributed to help IEM adult patients in better face this emergency time.