Trust in governmental organizations is a crucial factor in terms of encouraging people to conform to public health regulations, such as those recommended to slow down the spread of SARS-CoV-2. However, trust in governmental organizations tends to decline over time, reducing the compliance with public health regulations. This study aimed at exploring, first, the role of future anxiety and fatigue as serial mediators of the relationship between trust in governmental organizations and protective behaviors, and, secondly, the role of Covid-19 risk perception as a moderator between fatigue and protective behaviors. A total of 948 Italian participants (302 males and 646 females), ranged from 18 to 80 years (M = 27.20, SD = 11.01), answered an online survey during the second wave of the Covid-19 outbreak. A moderated serial mediation model was performed using a structural equation modeling. The results indicate that: (1) a higher trust in Italian governmental organizations was associated with a greater compliance in terms of adopting protective behaviors; (2) a lower trust in Italian governmental organizations increased anxiety about the future which, in turn, raised levels of fatigue, leading, finally, to a reduction in the levels of protective behaviors; and (3) as the perceived risk related to Covid-19 increased, the effect of fatigue on protective behaviors decreased. The findings of the current study may provide indications for public health policy on how to increase compliance with the recommended behaviors to be adopted in order to decrease the spread of the SARS-CoV-2.