reactivity, intrusive negative thoughts, model of insomnia, cognitive behavioral therapy To evaluate the relation between stress related sleep reactivity and metacognitive beliefs about sleep in subjects with Insomnia Disorder (93) and in a group of healthy controls (30) a set of variables, including Ford Insomnia Response to Stress Test (FIRST) and Metacognition Questionnaire – Insomnia (MCQ-I) have been used. Internal consistency of the Italian version of FIRST was studied. Univariate correlation, regression analysis and Principal Components Analysis were also performed. The Italian version of FIRST showed good internal consistency and discriminant validity. Sleep reactivity was higher in women (p<.05) and correlates positively in both genders with metacognitive beliefs about sleep (p<.01) in insomnia. In insomnia, metacognitive beliefs may play a key role in modulating sleep reactivity. Therapeutic strategies acting selectively on metacognition to reduce stress-related sleep reactivity in insomnia may be useful.