Since December 2019, the COVID-19 pandemic has attracted worldwide attention for its rapid and exponential diffusion. The long-term psychological impact, of both the spread of the virus and the restrictive policies adopted to counteract it, remains uncertain. However, recent studies reported a high level of psychological distress and Post-Traumatic Stress Disorder (PTSD) symptoms. The purpose of this study is to assess the psychometric properties of a new questionnaire, to evaluate PTSD risk related to the COVID-19 emergency. A total of Italian people completed a web-based cross-sectional survey broadcasted through different social-media. Demographic data and some psychological dimensions, such as general distress and sleep disturbance, were collected. A new self-report questionnaire (COVID-19-PTSD), consisting of 19 items, was developed starting from the PTSD Check List for DSM-5 (PCL-5) questionnaire, and it was administered in order to analyze its psychometric properties. The results highlighted the adequate psychometric properties of the COVID-19-PTSD questionnaire. The confirmatory factor analysis indicated that a seven-factor model (Intrusion, Avoidance, Negative Affect, Anhedonia, Dysphoric arousal, Anxious arousal and Externalizing behavior) best fits the data. Significant correlations were found among COVID-19-PTSD scores, general distress and sleep disturbance. A high percentage of PTSD symptomatology (29.5%) was found in the Italian population. COVID-19-PTSD appears to be effective in evaluating the specific stress symptoms related to the COVID-19 pandemic in the Italian population. These results are relevant from a clinical point of view because they suggest that the COVID-19 pandemic could be considered as a traumatic event. Psychological interventions to counteract short- and long-term psychopathological effects, consequent to the COVID-19 pandemic, appear to be necessary.