Objective: Informal care, defined as the unpaid care provided to an older, frail or ill person, by a person such as a spouse, parent, child, other relative, neighbour, friend, may lead to stress, burden and low well-being levels. As the phenomenon of informal care is growing, there is a need of psychological interventions in order to support informal caregivers. Evidence-based psychological treatments obtained good results in terms of well-being, but access to these treatments could be difficult for caregivers due to the of lack of time and financial strains. Internet-based interventions could be a possible solution within this scenario. "SOSteniamoci", an Internet-based Cognitive Behavioral Treatment program, consisting of 8 modules, will be adapted and tested in Italy. Methods: A randomized controlled clinical trial involving 128 informal caregivers will be conducted. Participants will be recruited from the Istituto Auxologico Italiano IRCCS1 and social media advertisements. After initial screening they will be randomly assigned to either an experimental group or a waiting list group. Expected results: During the last decade, internet-based cognitive behavioral interventions have been developed and tested. This therapeutic approach, due to its characteristics, could be beneficial in supporting informal caregivers. We expect this intervention to be feasible and efficient in reducing caregivers' burden, anxiety, depression and stress, while improving caregivers' quality of life and the quality of relationship with the care receiver.